IT IS NO secret that the War on Terror's prosecution has revealed fundamental differences between the United States and Europe over how to meet the challenges of global terrorism and jihadi Islamism. After the September 11 attacks, the United States chose a military response and considers itself to be engaged in a legally cognizable armed conflict to which the laws and customs of war apply. That view, although occasionally questioned by American politicians like Senator John Kerry (D-MA) during his unsuccessful 2004 presidential campaign, is supported by most Americans and is not likely to change regardless of who moves into the White House on January 20, 2009. This public sentiment aside, the nature of the American civilian legal system, which features many procedural and substantive protections that make it difficult to prosecute wartime combatants, especially those captured overseas, as well as the need to prevent rather than simply to punish terrorist attacks, effectively requires adoption of a war-fighting over a law-enforcement approach to transnational terror.

By contrast, governments Left and Right in Europe have evinced a clear preference for treating Al-Qaeda and other jihadists as a difficult, but manageable, political or law-enforcement problem. Moreover, not content with a "live and let live" strategy, they have sought to impose their legal and normative preferences on the United States and have reacted with varying degrees of disappointment, dismay and outrage at the Bush Administration's war policies. This is especially true of the president's decisions to classify captured Al-Qaeda and Taliban operatives as "unlawful enemy combatants", to detain them without criminal charge at Guantanamo Bay and to try them in military commissions rather than in civilian courts. If anything, attitudes in Europe have hardened since Congress enacted the Military Commissions Act of 2006. This law provides an explicit statutory basis for the president's policies and effectively vitiates the oft-invoked criticism that he employed the wartime legal paradigm solely on his own constitutional authority.

But more is at stake here than a tactical spat over how to deal with Al-Qaeda. There seems to be little doubt that Europe, or at least the European Union's leading countries, is consciously playing for the West's moral leadership, and Europe believes that it can win. Like it or not, the United States is now engaged in an ideological struggle resembling in some respects the ideological battles of the Cold War except that, this time, its closest friends and relations are in the opposition. Ask any cop on the beat; there is nothing more dangerous or dirty than a family fight, but this is a fight America must accept and win-for everyone's sake.

THE TRUTH is that, despite NATO's invocation of Article 5, accepting September 11's Al-Qaeda strikes as armed attacks against a member state, Europe has never thought of the War on Terror as a real war. As a high-ranking continental official once told the authors with feeling, "September 11 was a crime. It was a very great crime, but it was a crime."

The causes of this fundamental transatlantic difference in perspective appear to be twofold. First, Europe has had more experience with terrorist threats (albeit of the homegrown variety) than the United States and has managed to muddle through-although at a cost-without declaring a "war" on terror. In this regard, most European legal systems are simply better suited to investigating, interdicting and ultimately punishing terrorists than are America's civilian courts. Second, war has itself become an unacceptable concept in Europe, which has adopted so many legal limitations on the use of armed force that it is hard to imagine how European militaries could prevail in a serious conflict against a determined and ruthless transnational terror organization like Al-Qaeda. In a very real sense, Europe has not merely adopted a counter-terrorism model for law enforcement, it has also imposed the rules governing policing on its military forces, and it now expects the United States to follow suit.

Bonaparte's Justice-or the Founding Fathers'?

WITH THE notable exceptions of England and Ireland, Europe largely follows the civil-law criminal justice model, usually based today on some version of France's Code Napoleon. That system is grounded in Roman law and relies on an "inquisitorial" process-where the judges are active participants in finding the truth-for determining an accused offender's guilt or innocence. On the other hand, the common-law system, followed in England and many of her former colonies including the United States, uses an "adversarial" criminal procedure where judges act more as referees than investigators.

Overall, the civil-law system offers considerable advantages to the state in combating terrorism-especially in terms of investigative tools and a level of secrecy-that are simply unavailable in the ordinary common-law criminal prosecution and trial, at least as governed by the U.S. Constitution. And, while the law-enforcement model is never an optimum approach to dealing with global terrorist organizations that can project power and use force on a scale comparable to a traditional armed conflict, the European version of this model is at least semi-workable.

Civil-law criminal trials are not conducted before a jury in public as required by the U.S. Constitution's Sixth Amendment. Although serious offenses are almost always tried before a panel of three or more judges, and a number of civil-law jurisdictions (such as France) also provide for the participation of "lay" advisors or assessors, the civil-law fact-finding phase-during which much of the record is assembled-is fundamentally different than in common-law countries. In the United States, the record upon which the accuser's guilt or innocence is determined is compiled during the trial itself, with the judge acting as a legal umpire and the jury the ultimate arbiter of fact. In this process, the source, nature and legal sufficiency of all evidence is critical, as the jury can only find the facts based upon evidence that is, and has been, determined to be admissible and presented in open court.

By contrast, in civil-law systems, the record is made through a process of inquiry (or inquisition) by an investigating judge or magistrate. Throughout this stage of proceedings, the magistrate is assisted by the police, who act under his direction. (The police are also, of course, involved in the pre-judicial phases in identifying the suspect and providing sufficient evidence to the prosecutor who determines whether to refer the case to an investigating judge.) In France, for example, although there are certain limits to when and how a search can be conducted, the police do not need a search warrant-in the form of a judicially issued, particularly defined order based on a probable-cause showing-to obtain evidence from or against a suspect.

Moreover, the investigating magistrate has broad authority to seek out almost any information he believes will assist in establishing the truth. Although the trial record in an American criminal case consists only of the legally admissible evidence presented by the prosecution and defense before judge and jury, the civil-law record (which will at least be available to the trial judges, although not necessarily to any lay assessors) includes all the evidence the investigating magistrate considered to be useful in determining what actually happened.

In addition, introduction of evidence into the record is not limited by the type of very narrow evidentiary rules prevailing in the United States. The civil-law trial bench usually has broad discretion to allow inclusion of any evidence it considers useful for determining the truth. Thus, for example, hearsay evidence is commonly accepted as part of the record in civil-law countries, even though its admission in the United States (apart from certain exceptional circumstances) would be considered a violation of the defendant's right to confront the witnesses against him.

Also, this critical investigative stage of the proceedings is conducted in private. Access to the file is eventually granted to defense counsel-in France, for example, shortly before the suspect is first formally examined as the accused-although much of the investigatory work will have very likely been accomplished by this time. However, as a rule, there is no public right of access. The trial itself, where the record is supplemented by the oral testimony and argument on which a decision is supposed to be based, is generally public, although these proceedings can also be closed for reasons of public policy or public morality. This, of course, is another critical difference between the civil-law system and common-law jurisdictions, where the record is made at trial and in public with the narrowest of exceptions.

The civil-law investigating judge can also order pre-trial or "investigative" detention for the accused. This authority, which (in France at least) is supposed to last no more than a year but can involve much longer periods, is widely used. There is no constitutionally mandated presumption for a reasonable bail in most civil-law jurisdictions as there is in the United States. Indeed, very lengthy pre-trial detention is one of the most common and persistent human-rights abuses identified in the State Department's annual human-rights country reports with respect to the major European democracies. From 1999 through 2005, for example, lengthy pre-trial and trial detention was identified as a problem in Spain, France, Italy and Belgium-and could be fairly described as especially acute in the latter three countries. In 2005, 35 percent of the French prison population were individuals awaiting trial; in Italy, nearly 40 percent were pre-trial detainees, 38 percent in Belgium and 20 percent in Spain.

In addition, a number of European countries also have adopted a prolonged period during which terrorism suspects can be held before being brought before a judge or magistrate. Germany permits courts to order the continued indefinite detention of individuals convicted of rape, homicide or manslaughter after a sentence is served if it is determined that the individuals could be dangerous. Similarly, Italy permits preventative detention of up to two years (during preliminary investigation) in serious cases such as terrorism, illegal drugs and arms sales, and in offenses involving the Mafia.

American courts, on the other hand, have permitted preventative detention only as a limited exception to the general rule against pre-trial imprisonment. This rule is buttressed by the Constitution's prohibition of excessive bail (in those cases where bail is properly available) and, especially, its speedy trial requirements. Although the courts have not defined, as a constitutional matter, the precise period of pre-trial delay considered to be impermissible, under the federal Speedy Trial Act, an accused must generally be brought to trial within one hundred days of arrest or service of a summons-although a longer period is very often agreed to by defense counsel so as to have adequate time to prepare. Moreover, again with limited exceptions involving post-incarceration restrictions on sex offenders, involuntary mental health commitments and certain immigration-related processes, the United States does not have administrative detentions.

Finally, European states have had far more experience (and are much more comfortable) with paramilitary police forces, such as France's Gendarmerie Nationale, Italy's Carabinieri or Spain's Guardia Civil. In contrast, the formation and use of paramilitary policing bodies (like the Detroit Police Department's stress unit in the late 1960s and early 1970s) have been highly controversial and, except for some small swat teams, generally unsuccessful. Meanwhile, the federal Posse Comitatus Act prohibits, as a matter of law, the military from participating in most law-enforcement operations.

So the "law-enforcement" counter-terrorism model employed by Europe is emphatically not the civilian court system known in the United States. And, as a result, the question for Americans really is not whether we should rely on the civilian legal system rather than the laws of war as the normative framework for regulating the fight against Al-Qaeda. It is whether, so as to avoid the extraordinary resort to war that makes our European allies so uncomfortable, the American legal system should be fundamentally changed in ways that would more closely approximate the civil-law system. Should we-as the British did in dealing with the IRA threat in the 1970s and 1980s-make fundamental compromises in our legal and constitutional traditions, in essence dispensing with many of the protections afforded by the Bill of Rights? And, the policy merits of this approach aside, it is doubtful whether the U.S. Constitution would permit such expedients as part of the civilian justice system.

The experiment, however, is unnecessary since the laws of war, as recognized by the United States, offer a far less drastic alternative that does not even temporarily alter the nature of our civilian judicial system. American law has always recognized that the rights of civilians and combatants are fundamentally different. The United States has maintained these distinctions even if Europe has not-and this also accounts for its clear preference for a law-enforcement counter-terrorism paradigm.

AS EUROPE honed its criminal justice systems to address terrorism over the past fifty years, its military capacity deteriorated. Defense spending by EU states has generally declined as a portion of real GDP, and these states also have adopted stringent rules governing the application of military force that actually favor the irregular tactics used by Al-Qaeda and its allies. Both phenomena are supported by increasingly hostile attitudes towards armed conflict as an answer to virtually any problem-including armed aggression by others.

Even if Europe were to change its defense posture in the coming decades-say, in response to a decreased U.S. security commitment-modifying the European legal regime governing armed conflict will be far more difficult, if not impossible. This is especially true because this regime has now been institutionalized (by, among other things, the creation of the International Criminal Court to which all EU states are subject), to an extent that would make serious reform, except in the most catastrophic of circumstances, a Herculean task.

The most important impediment to change is Europe's general acceptance of Protocol I Additional to the 1949 Geneva Conventions, as well as application of various EU human-rights treaties to military operations, and its prevailing interpretation of international law to permit only two legal statuses under the law of armed conflict-combatants, who are entitled to prisoner-of-war (POW) status on capture or surrender, and civilians, who must be treated as criminal defendants if caught in a hostile act. Protocol I effectively eliminates a traditional third category, the "unlawful" or "unprivileged" combatant.

Under the Geneva Conventions, lawful belligerents or combatants are honorable soldiers associated with a sovereign state-private individuals or groups have no legal right to use force as a means of achieving their goals. All lawful combatants also meet four minimum criteria: They must be affiliated with a group that has a recognizable command structure, wear uniforms, carry their arms openly and conduct their operations in accordance with the laws and customs of war-including and especially the injunction against targeting civilians for attack or operating out of civilian areas. As noted in the British Military Manual used during both world wars, "It is taken for granted that all members of the army as a matter of course will comply with the four conditions; should they, however, fail in this respect they are liable to lose their special privileges of armed forces."[1] Upon capture, lawful combatants are accorded POW status, carrying with it both numerous benefits and connotation of honor.

By contrast, those who engage in hostilities, but do not meet these criteria, are properly classified as unprivileged combatants under traditional international law. They enjoy neither the rights granted to civilian criminal defendants nor receive the very important privileges of POWs. Application of Protocol I to captured jihadists and other unlawful combatants changes this rule, requiring that they be treated effectively as POWs, including communication rights through the International Committee of the Red Cross and a highly restrictive standard regarding interrogations.

In addition, Protocol I provides numerous other advantages for unlawful combatants and has been used to justify increasing demands (especially by humanitarian and human-rights NGOs) that regular forces adopt tactical practices in the field designed with what amounts to a zero tolerance of "collateral damage"-i.e., unintentional injuries to civilians and civilian property. Thus, although the traditional laws of war forbid deliberate attacks on civilians and require the likely benefit of military operations to be proportionate to any likely unintentional damage to civilian objects, Protocol I is said to require that all military operations be carried out so as to minimize damage to civilians or civilian objects.

Terrorists, of course, purposefully hide among the civilian population, making it virtually impossible for a Protocol I-compliant state to defeat them decisively without garnering claims that it has committed "war crimes." Indeed, at a minimum, the treaty deprives regular state forces of advantages they may have from greater potential firepower, while advantaging irregulars by effectively permitting them to use the civilian population as a shield without any perceptible legal cost. Israel's ineffectual 2006 offensive against Hizballah is a textbook example of how following Protocol I-type rules substantially evens the odds between regular forces and irregulars. Protocol I gives terrorists the best of both worlds-which is why the United States rejected it during Ronald Reagan's presidency.

The Great Divorce

IN REAGAN'S day, of course, this divergence between the United States and its European allies over the law of armed conflict was a largely theoretical problem, but no longer.[2] In a post-September 11 world, effective and genuine joint operations between the United States and many of its NATO partners have become impossible. Thus, although NATO is now "engaged" in Afghanistan, American forces continue to bear the brunt of actual fighting. The German contingent avoids contact with "armed elements" in Afghanistan, and Dutch commanders have made clear that they would go to extraordinary lengths to ensure that their troops were not killed in combat. Among the primary allied objections have been that their troops are not trained for counter-terrorism operations and the U.S. position with respect to prisoners.

The disputes over classification and treatment of captives has also adversely affected U.S. cooperation even with those NATO forces that are able and willing to fight, notably the British Army. (Canadian and French forces also participate in combat and combat-support operations in Afghanistan.) As a senior British officer explained to one of the authors, British forces do not willingly transfer captured Al-Qaeda or Taliban prisoners to the United States, lest they be later accused of facilitating "unlawful" treatment, and these same forces live in fear of capturing a senior leader like Bin Laden, lest they be seen as protecting him from American custody.

At the same time, European elites, activists and governments have undertaken a determined campaign to delegitimize America's resort to the traditional laws-of-war paradigm in the hope of forcing a change. This effort has manifested itself in a number of different ways. Individual European political leaders-including those ostensibly supportive of the United States, like Germany's Angela Merkel-and the EU have persistently condemned American detainee policies, and have demanded closure of the Guantanamo Bay facilities. Even British Prime Minister Tony Blair, who has paid a heavy political price for his indefatigable commitment to fighting global terror and jihadi violence, has labeled Guantanamo Bay (and the policy it represents) an "anomaly." The British government, in the form of Attorney General Goldsmith, has questioned the legality of "indefinitely" detaining enemy combatants and its official position is that Guantanamo Bay is "unacceptable."

In addition to these efforts at generating international political pressure, hundreds of members of the British and European Parliaments have interposed themselves in the U.S. domestic debate over the rights and treatment to be accorded Al-Qaeda and Taliban detainees, filing friend-of-the-court briefs (in the Supreme Court and lower federal courts) in a number of War on Terror cases, including Rasul v. Bush (dealing with federal court jurisdiction over Guantanamo Bay) and Hamdan v. Rumsfeld (dealing with the legality of military commissions).

More recently, Germany and Italy have undertaken prosecutions of individual Americans based on U.S. War on Terror policies. A German court recently issued arrest warrants for thirteen CIA agents for detaining (in Macedonia) a German national on suspicion of Al-Qaeda ties and transporting him to Afghanistan for interrogation. Similarly, Italian prosecutors in Milan have brought indictments against several CIA agents for allegedly taking an imam from Italy to Egypt in an act of "extraordinary rendition." Another Italian court has also ordered an American soldier to be tried in absentia for killing an Italian intelligence officer (who failed to stop for a U.S. checkpoint) in Baghdad, even though the man was exonerated after a U.S. Army investigation.

Although these various efforts-diplomatic, political and judicial-have not yet worked a significant change in U.S. policy, the outcome of this ideological struggle is highly important. This is because-at least in the West-compliance with the rules of warfare has always mattered. Contrary to popular depictions of war, far from being the domain of pure unbridled violence, armed conflict has always been a highly organized affair driven by an elaborate set of rules-in large part because the act of killing human beings requires a great deal of legitimacy to justify it, as compared with normal peacetime pursuits. Accordingly, it is law that provides the necessary legitimacy for key aspects of war, such as how it is launched, how it is prosecuted and the nature of the post-conflict settlement.

What is remarkable about the European assault on the legitimacy of Washington's preferred legal architecture for fighting the War on Terror is its determination to hamper the use of American power even when that use may be, broadly speaking, in European interests. Anti-Americanism has, of course, been a growing phenomenon in Europe since well before the War on Terror began. Its seeds, certainly, could be discerned even before the Cold War ended-in elite European attitudes towards the Reagan Administration's efforts to modernize NATO's defense systems (and has arguably been something of a norm when the sweep of American history is examined). Today, the attitude appears to be "Anybody but the United States." This is rather like the 15th-century Byzantine statesman Lucas Notaras who proclaimed "better the Sultan's turban than the Cardinal's hat", in response to suggestions that Constantinople seek assistance from the Western states in its final struggle with Islamic jihad.

Indeed, there are a number of intriguing parallels between contemporary European attitudes towards the United States and the opinions of the later Byzantines towards the Western European states then growing in power and influence on the international stage. As the senior heirs of a shared religious, cultural and philosophical heritage, the Byzantines viewed these ascendant states at best with an air of amused superiority and often with a vague (and sometimes explicit) contempt. As a Greek historian noted with respect to Westerners at the beginning of the 13th century:

Between us and the Latins is set the widest gulf. We are poles apart. We have not a single thought in common. They are stiff-necked, with a proud affectation of an upright carriage, and love to sneer at the smoothness and modesty of our manners. But we look on their arrogance and boasting as a flux of the snivel which keeps their noses in the air.[3]

Also, the later Byzantines displayed a marked derision for military solutions (diplomacy was very much more their line) at a time when their own armed strength was at a low ebb. The belief that defeat by the Turks was preferable to rescue by the West (although it is not at all clear that this could have been accomplished by a divided West at the time) was, of course, not shared by all Byzantines any more than anti-Americanism is shared by all Europeans. In the end, however, the Sultan's turban is exactly what they all got-and the "Latins" of the West ended up with a real and immediate threat in the very heart of Europe. In other words, everyone lost.

At any rate, whether driven by a Byzantine-style hostility towards its American cousins, by the instinctive desire of all children of the Enlightenment to validate policy choices in moral terms or by a more utilitarian impulse to impose legal restraints on the use of American power which they are otherwise unable to constrain, Europe's decision to challenge the United States on the terrain of law and values is a very serious matter. There can be little doubt that the relentless attacks by European officials and opinion-makers on virtually every one of the Bush Administration's War on Terror policies (even those fully supported by Congress, such as the initial decision to deploy military force against Al-Qaeda and the just-enacted Military Commissions Act of 2006) have undermined support for the American position in Europe and in the United States itself. What these officials have not offered is a plausible alternative that does not require fundamental changes in the American judicial system or expose the civilian population to additional and unnecessary risk.

The Bush Administration did not, following the September 11 attacks, invoke the laws of war on a lark. Nor, despite the tortured (and increasingly tedious) dreams of the president's domestic political enemies, did George W. Bush adopt a "war paradigm" as a means of increasing his personal power. Armed conflict was, and remains, the only legal framework through which the United States could effectively confront Al-Qaeda, taking direct action against its bases and assets around the world. Supporters of the criminal-enforcement model, whether in Europe or America, have never grappled with this stark reality and all of its implications. The key one is that, detention issues aside, if Al-Qaeda and other jihadists are merely criminals, then they cannot be attacked by the military-regardless of where they are or what they are doing. Criminal suspects must be arrested, ordinarily pursuant to a lawful warrant. They cannot just be killed.

Indeed, even the civil law, for all of the advantages it gives prosecutors, does not countenance the extrajudicial killing of suspects. And, if the law of armed conflict is not properly applicable, that is precisely what attacks on terrorists and their bases would be-including the Clinton Administration's 1998 cruise missile attacks on six Al-Qaeda camps in Afghanistan and what appears to have been a pharmaceutical factory in Sudan. The lawful alternative would be to investigate, gather evidence against any individuals who have been identified (if they can be identified) and seek indictments and international arrest warrants. If a government sympathetic to the terrorists in question chose not to honor such warrants, it could effectively shield them from retaliation or justice for their actions since military action would arguably be an act of illegal aggression. In this legal framework, officials of the state who launched an attack on the state harboring the terrorists may well be subjected to criminal liability by an international or domestic tribunal.

At the same time, although a state's permitting the combatants (lawful or unlawful) in an armed conflict to train, plan operations and even launch attacks from its territory against another state would clearly be a casus belli-supporting the use of force in response-it is not at all clear that merely refusing to honor warrants for "criminal suspects" would be sufficient to justify a military attack. Indeed, even the UN Security Council might not be able to authorize the use of force in such a situation.

Other types of pressure could, of course, be brought to bear on a terror-friendly state, but the record of similar past efforts is not promising. Despite a serious sanctions regime, Libya agreed to pay compensation for the destruction of Pan Am Flight 103 only after the United States deployed major military assets against terrorists and their state backers in the region. Abu Nidal, a Palestinian terrorist responsible for more than twenty terrorist attacks killing hundreds of people, lived safely in Libya and Iraq until Saddam Hussein was deposed. Moreover, the criminal justice system's proven inability to prevent attacks by determined, and especially by suicidal, terrorists on the civilian population suggests that reliance on the law-enforcement model would result in additional and unnecessary deaths.

In fact, the United States can physically disrupt Al-Qaeda's overseas operations only if it is at war, and therefore has the legal right to attack and destroy terrorist bases, training centers and operations centers without warning. That said, admittedly, the "War on Terror" was always an unfortunate formulation. Terror, obviously, is a tactic, not an enemy. The Bush Administration appears to have chosen this phrase-whose roots can be traced to the even more politically correct Clinton Administration's claim that the "target" of its 1998 anti-Al-Qaeda strikes was "terror"-not for legal precision, but because it is broad enough to cover wide-ranging hostilities against Al-Qaeda and its many jihadi allies, yet (theoretically) ambiguous enough to avoid giving offense to the Muslim world at large. Unfortunately, as with so many definitional compromises, the term "War on Terror" has caused as many problems as it has solved.

As a legal matter, however, the United States' enemy is-and always was-Al-Qaeda, its allies, including the Taliban, and other jihadists who have joined the fight. Al-Qaeda was responsible for the September 11 attacks, and Congress formally authorized the use of American military force against those responsible, and anyone giving them assistance or refuge, on September 18, 2001. In American law, such authorizations are the practical equivalent of a declaration of war, although of a more limited scope, as the United States Supreme Court has recognized since Congress authorized naval hostilities against Revolutionary France in the 1790s.

At the same time, under international law, the concept of "war" or "armed conflict" has never been limited to fighting between sovereign states. There is certainly no established international norm forbidding a state's invocation of the law of armed conflict when militarily engaging a non-state actor. It is true, of course, that states have rarely declared war on non-state entities. But that formality has not been considered necessary to the existence of a legal state of war at least since the 18th century. As Emmerich de Vattel explained in his 1758 Law of Nations: "He who is attacked and makes only a defensive war, need not declare it, the state of war being sufficiently determined by the declaration of the enemy, or his open hostilities." Indeed, today it is the nature, intensity and duration of hostilities that determine application of the laws of war, rather than any formal declaration.

By that standard, the United States has been engaged in an armed conflict with Al-Qaeda since the 1990s (thus legally justifying President Clinton's 1998 strikes), when Osama bin Laden began deliberately to target American interests-including United States diplomats in Kenya and Tanzania, U.S. military personnel in Saudi Arabia and the USS Cole in Aden harbor. The September 11, 2001, attacks were certainly acts of war in terms of their nature, scope and level of violence. Indeed, they were classic examples of a pre-emptive strike designed to knock out the enemy's political, military and financial leadership. Al-Qaeda's 9/11 targets-the Pentagon, the World Trade Center and (most likely) the United States Capitol-were emphatically not selected simply to terrorize the civilian population.

The fact that Al-Qaeda is not a state, and has no legal right to make war against states, does not change this analysis. Al-Qaeda cannot legally make or declare war against the United States, but the United States is fully entitled on its part to invoke the laws of war to govern hostilities with Al-Qaeda. And it is bound only by the treaties it has ratified; the United States rejected Protocol I, and is properly considered a persistent objector to any customary international-law norms that may be forming around that instrument. Its detention of captured jihadists may not be consistent with the obligations of European Union states, but America is not an EU member or a candidate for membership.

INVOKING THE laws of war has permitted the United States both to confront Al-Qaeda and to preserve its own institutions. This was the right decision, and remains so. Given the stakes involved, the United States should continue to eschew the embrace of the European-style law-enforcement approach for dealing with the jihadi threat. At the same time, however, it must engage in an assertive advocacy of the legal and policy merits of using war's distinctive legal architecture to meet this threat-not because there is much hope of winning over European governments (barring a major escalation in the level of terrorist violence on European soil)-but to vindicate the American position and ensure its continuation as the only viable means ultimately of stopping Al-Qaeda.

In this regard, the U.S. response must go beyond "business as usual" bureaucratic policymaking, in which conflict avoidance with our allies routinely takes precedence, and legal issues are generally viewed as relatively unimportant. Whenever the Europeans accuse the United States of not being true to our common values or violating international law, we should respond with equal vigor and passion. In particular, the United States should not always be on the defensive and should be prepared to challenge the European resort to the "illiberal" law-enforcement measures. Legal and policy démarches should be issued frequently and at the highest level, with a particular emphasis on why the use of the law-enforcement paradigm is inadequate and the utilization of the laws-of-war paradigm is both legitimate and lawful.

David B. Rivkin, Jr. and Lee A. Casey are partners in the Washington, DC office of Baker Hostetler LLP, members of the UN Subcommission on the Promotion and Protection of Human Rights and have served in a variety of legal and policy positions in the Reagan and George H. W. Bush Administrations. They are writing a book on war's evolving legal architecture.

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