SINCE WORLD WAR II—the largest military effort ever by the United States, and one ending with clear victory—the use of U.S. military force overseas has exhibited two patterns. One is the increasing frequency and duration of the application of force. This trend has become especially noticeable since the turn of the twenty-first century, with the United States fighting its two longest major military campaigns, in Afghanistan and Iraq. Simultaneously, Washington has conducted combat operations in Libya, Syria and elsewhere, all under the indeterminate rubric of “war on terror.” An entire generation of Americans has come of age with its country perpetually at war.

This state of permanent warfare is hard to explain in terms of national self-image. Americans have traditionally seen themselves as peace-loving folks who strike back only when someone else picks a fight. In the words of John Quincy Adams, they tend not to seek out “monsters to destroy.” The United States has not been a latter-day Sparta, defining its virtue in terms of martial spirit.

The second pattern makes the first even more difficult to comprehend: the overall results of all this fighting overseas have been poor. Uncle Sam has regularly cried “uncle.” The Korean War ended in a draw. The only major U.S. war since then to register a win was Operation Desert Storm, the expulsion of Iraqi forces from Kuwait in 1991. The other large U.S. military campaigns of the last sixty years fall on the opposite side of the ledger. They include the Vietnam and Iraq fiascos, as well as a war in Afghanistan that has gone on for fourteen years and shows no sign of ending. More modestly sized uses of air power have brought only mixed results: some success in the Balkans in the 1990s, but extremist-infested chaos in Libya after the intervention in 2011. Smaller U.S. operations on the ground also have had mixed outcomes, ranging from achievement of some modest objectives in the Caribbean to significant U.S. casualties in, and an embarrassing withdrawal from, Lebanon in the early 1980s.

The United States has been employing military force overseas more than what prudent pursuit of its interests would call for. Yet it keeps coming back for more. An impulse for more foreign military expeditions, despite its poor record, is reflected not only in the two-decade trend toward permanent warfare but also in current pressure in American public debate to do still more militarily in the Middle East. This impulse is not just a matter of policymakers misunderstanding foreign conflicts. More fundamental elements of American thinking are at work and are affecting today’s debates about military force in Syria, Iraq and Afghanistan.

ONE POSSIBLE way to explain the trend toward permanent U.S. engagement in warfare concerns long-term changes in the international system and the position of the United States in it. There is some validity to this approach. The United States evolved into a superpower with the increased opportunities and responsibilities that come with it. But the ability to project military power across the globe does not imply that it is prudent to do so, particularly given the United States’ string of poor results. Political scientist Barry Posen explains that although the unmatched ability to project military power gives the United States command of the global commons (e.g., sea lanes and international air space), it does not give Washington the ability to control events wherever it wants. The expansion of U.S. military capabilities has prompted excessive applications of force, much as a person who owns a nifty hammer tends to perceive nails everywhere.

Theories elevating terrorism to a new and systemic threat wield little explanatory power. Granted, the September 11, 2001 terrorist attacks did trigger an abrupt change in the American public mood. But international terrorism has been around for centuries and has been shaping U.S. interests for many decades. America’s recent military misadventures cannot be sufficiently explained by the rise of terrorism. The costly expedition into Iraq had nothing to do with terrorism, notwithstanding contorted efforts by the promoters of that war to capitalize on the martial post-9/11 public mood.

A traditional explanation for resorting to arms focuses on the vested interests of particular stakeholders. In the United States, this thesis has been most popular on the left, but has had a wider cachet ever since Dwight Eisenhower spoke about a military-industrial complex. Of course institutional biases exist, but the attitudes expressed by the U.S. institution most involved in the use of force—the military—do not support the thesis. The military tends to favor full application of resources to assigned missions, not the undertaking of new missions. It was a civilian policymaker, Madeleine Albright, who asked the nation’s top military officer, Colin Powell,“What’s the point of having this superb military that you’re always talking about if we can’t use it?” Today’s senior military officers are exhibiting some of the same caution that Powell did. In a recent hearing of the Senate Armed Services Committee that addressed the possibility of establishing a no-fly zone in Syria, the vice chairman of the Joint Chiefs of Staff, Gen. Paul Selva, remarked that “we have the military capacity to impose a no-fly zone,” but “the potential for miscalculation and loss of American life in the air” render the idea unwise. The hawkish and disappointed committee chairman, John McCain, referred to this testimony as “one of the more embarrassing statements I have ever heard from a uniformed military officer.”

THE INFREQUENT use of military force in America’s earlier history informs today’s frequent use. Blessed with physical separation from foreign threats, Americans adopted the non-Clausewitzian habit of thinking about military means and political ends as two separate realms. They thought about war as the last resort, sallying forth abroad to eliminate whatever threat was sufficiently serious to justify such an expedition. Unlike the Europeans living with continuous threats at close quarters, Americans did not have to develop ways of thinking about security and military force that were more balanced and sustainable over the long term even with more permanent and intense engagement with the outside world.

But after World War II, the American superpower did become permanently and intensely engaged with the rest of the world. It was the sort of engagement that Americans were used to associating solely with wars, some “colder” than others. Thus an irony of American history is that the infrequency of wars in the nineteenth century helped to shape a national outlook that, combined with requirements of America’s global involvement in the twenty-first century, has brought Americans close to believing themselves to be in perpetual war. The belief has helped foster the reality.

The optimism that post–World War II Americans have exhibited as to what can be accomplished through force is rooted in the remarkable success that the United States enjoyed while rising to a position of unparalleled power. After all, military force produced an impressive winning streak through World War II. Even the one earlier war that should be scored as a draw—the War of 1812—was perceived by many Americans at the time as a win because combat ended with a smashing American victory at New Orleans. Even the Civil War that tore the nation apart later in the nineteenth century was ultimately a successful application of arms: a rebellion was quelled, the union was preserved and the country emerged freer than before.

America’s military successes have been so obvious, so long-standing and so deeply embedded in American culture and lore that they still shape current discourse on the use of force. That history, ingrained in American habits of thought, impedes the learning of lessons from more recent and less successful uses of force. The history is part of what lies behind McCain’s belief that it should not be too hard for “the most powerful nation on Earth” to set up a no-fly zone or to “take out” the so-called Islamic State.

Most of the wars the United States fought while still on a winning streak did not confront it directly with the nationalism-soaked problems that U.S. military interventions have encountered since the streak ended. The United States got its first real taste of such problems dealing with a stubborn insurgency in the Philippines after taking the islands from Spain following an easy win in the Spanish-American War. The lessons from that experience were not fully applied to a bigger insurgency elsewhere in Southeast Asia half a century later. Robert McNamara, the U.S. secretary of defense during the first half of the Vietnam War, wrote many years afterward with insight and anguish,

“We underestimated the power of nationalism to motivate a people (in this case, the North Vietnamese and Vietcong) to fight and die for their beliefs and values—and we continue to do so today in many parts of the world.”

IN MANY of America’s more recent foreign expeditions, resistance to applications of U.S. military power stems not only from such strong nationalist sentiment but also from widespread perceptions of U.S. power as threatening rather than helpful. The difficulty most Americans have had in recognizing such perceptions and the problems they pose for U.S. military campaigns emanates from the benign American exceptionalist self-image. It also has historical roots in the geographic isolation that gave citizens of a younger and weaker United States the luxury of not having to think much about how someone else’s projected power can feel threatening.

What should have been sobering lessons from the more recent and less successful military interventions have tended to be swept aside in favor of the historically based optimism about the utility of force. The “Vietnam War syndrome”—a public hesitance about such interventions after the nation got so badly burned in that war—was largely blown away by the inspiring success of Desert Storm. Although the Iraq War is deeply relevant to the ISIS situation, the lessons of that costly expedition have been compartmentalized and largely lost.

Some who supported that war explain it away as all about a mistake, not to be repeated, concerning nonexistent weapons of mass destruction. Donald Trump has tried to inoculate himself by claiming, with some exaggeration, always to have opposed the Iraq War, but such opposition has not deterred him from calling on Washington to “bomb the sh-t” out of ISIS. Ted Cruz’s attempt to do something similar with his criticisms of neocons has not stopped him from calling for carpet bombing in Syria. Many Republican opponents of Barack Obama cling to the myth that the president snatched defeat from the jaws of victory by implementing the troop withdrawal agreement negotiated by the Bush administration—a myth that disregards both the substantial pace at which the Iraqi civil war was still being fought at the time and the failure of earlier military efforts to resolve the political conflicts that underlie instability in Iraq today.

Beyond all of this is a frequent admonition not to “overreact” to the bad experience of the Iraq War, an admonition voiced so frequently that it has become an overreaction about overreaction. Coupled with that theme are efforts to depict any proposals for more military intervention in the Middle East as much different in cost and duration from the quagmire that the Iraq War became. Typical is the urging by James Jeffrey, ambassador in Baghdad and a White House policy adviser in the George W. Bush administration, to initiate a U.S. ground war against ISIS, which he assures us would be a “short,” “crisp,” “rapid takedown” of the group. Similar spin comes from columnist Richard Cohen, who is more interested in using force against the Assad regime than against ISIS and says that a no-fly zone and “maybe taking a shot or two at a key government installation” would do the job. The relevance of lessons from the Iraq War simply gets defined away with unrealistically sanguine images of what the next war would look like.

Certain other rhetorical dynamics of current debates about the use of force in Syria and Iraq add to the historically based bias in favor of using it. One is the American habit of discussing almost any serious issue overseas as a problem that the United States can and should solve. A related rhetorical asymmetry is the greater appeal of positive, confident-sounding calls for the United States to do just that, compared with the lesser appeal of caution or skepticism about whether the United States really can solve other people’s civil wars. Saying anything that sounds like, “that’s a nasty problem, but given the downsides of our available options, we’ll have to live with it” does not win American political leaders votes.

The public and political appetite for action usually means specifically visible, forceful action. That means that military responses have greater appeal than less visible policy tools, such as behind-closed-doors diplomacy. Amid today’s Middle East security issues, the “war on terror” concept continues to weigh heavily on American debate and foreign-policy discourse. It is a metaphor that has shaped reality. It has led to the false syllogism that if a problem is serious then America is at war, and if America is at war then it needs to use military force to solve the problem. The influence of this line of thinking is heard in the frequent declarations from Republican presidential candidates and others that “we are at war,” notwithstanding the absence of a congressional declaration of war.

A related pseudologic equates leadership with toughness, and toughness with military force. Barack Obama has been especially vulnerable to criticism of his leadership along these lines, given his image as a pedantic law professor who came into office eager to withdraw from existing wars and whose administration has been said to “lead from behind.” The lack of appeal, emotionally as well as politically, of this presidential style has led commentators not normally hostile to Democrats to complain about Obama’s unwillingness to amp up his rhetoric. Dana Milbank of the Washington Post calls him “President Oh-bummer” and says although tough talk won’t defeat terrorists “it will rally a nation.” Milbank’s Post colleague Richard Cohen says Obama’s approach leaves him “empty and cold.” Cohen observes that Obama “is a cautious man who fears his rhetoric running away from him”—an accurate statement about the president’s concerns that also points to an actual process of rhetoric pushing policy, another reason that the use of military force has gone beyond what is in the nation’s best interests.

Other dynamics compound this trend in Washington’s approach to the Middle East. One is the luxury that political opponents have, and incumbent policymakers do not, of sounding appealing themes without having to voice less appealing cautions about long-term complications and consequences. Amid fears of terrorist groups and a presidential election, the rhetorical energy drives predominantly in the direction of more rather than less reliance on military force.

Another factor is the universal human tendency to treat sunk costs as investments. This tendency has especially affected American discourse about Iraq, and all the more so given propagation of the myth that the United States was on the verge of a victory there in 2009. Politicians and military veterans alike relate news about the latest fighting in Iraqi cities to sacrifices that U.S. troops made in the same locales during an earlier phase of the war. Such connections are drawn even though sunk costs really are sunk and past ill-advised expenditures have not bought any current opportunities.

At some level of consciousness the Pottery Barn rule—if you break it, you buy it—has affected American thinking about troublesome military expeditions, adding to the impetus to escalate and extend rather than to retrench and curtail. By itself the rule is laudable and teaches responsibility. The trouble is that the rule tends to get applied only after breakage has occurred. And with Americans thinking of themselves as builders rather than breakers, some commitments have been made with insufficient advance thought about what was likely to be broken.

All of the aforementioned factors have contributed to Washington’s current state of unending warfare and of perpetuating the costly pattern of using military force beyond what careful consideration of U.S. interests would dictate. Among recent military expeditions, the invasion of Iraq remains a glaring example of how not to apply force—blind to the troubles that would spill out once Iraqi pottery got broken and with unrealistically rosy assumptions about how liberalism and democracy would fall into place after a dictator’s ouster. But that war was an extreme case, given the extraordinary absence of any policy process to consider whether launching the war was a good idea and thus insufficient opportunity within the government to question the rosy assumptions and to consider all the possible costs and consequences.

PERHAPS MORE illustrative of the general point about the American bias toward war have been the policies of, and pressures upon, Obama, who by contrast has deliberated meticulously (“dithering,” to some) about applications of military force. He has tried to resist demands to expand the unproductive record of unending warfare. He has succeeded in resisting some, but has succumbed enough to disappoint followers who wanted a president who would be getting Americans out of wars rather than keeping the nation immersed in them. The political pressures from those followers have been much weaker than pressures coming from the opposite direction. Obama has had to deal with a Congress in which one chamber for most of his presidency, and both chambers for his final two years, have been controlled by an opposition party whose foreign policies have been dominated by neoconservatism. His first secretary of state and aspiring successor is more hawkish than he and is part of an element in his own party that favors armed intervention on humanitarian grounds, which was the rationale for the operation in Libya. The perceived trait that Obama, fairly or unfairly, continually has had to counteract is wimpiness, not recklessness.

The administration’s first test was the war in Afghanistan. Long before President Obama entered office, the United States had failed to find an off-ramp. Once the Taliban had been ousted from Kabul and Al Qaeda rousted from its haven, the United States could have opted for an honorable conclusion to its justified military response to a major terrorist attack, before the operation morphed into a nation-building exercise in the graveyard of empires. The more time that passed after the successful ousting and rousting in the first few months of Operation Enduring Freedom, the less honorable any exit would have seemed. Moreover, for Obama in particular, Afghanistan was the “good” war in contrast to the “bad” war in Iraq, which to his credit he had opposed from the beginning. So a complete exit while Afghan factions continued to wage their civil war was not in the cards. The policy response included a surge that always made more domestic political sense than military sense, being too small and quick to accomplish much on the ground. The administration’s response also has come to include a scotching of any idea of an exit in the foreseeable future, an apparent acceptance of indefinite extension of what already is America’s longest war. All this in a country that, notwithstanding the association with 9/11, has taken its place in modern history because of an insurgency more than three decades ago against a client regime of the Soviets. Afghanistan is not inherently destined to be enmeshed in international terrorism, and whatever strategic significance it has is incommensurate with the longest ever U.S. war.

Some of the same psychological and political tendencies in the American approach to countering terrorism have been apparent in the use of unmanned aerial vehicles, or drones, to kill suspected terrorists. Lethal operations with drones began in 2002 under George W. Bush, and the Obama administration has increased their pace. The appeal of drones is partly as another splendid hammer that cries out for nails to be struck. More significantly and defensibly, drone strikes have been the only practical way to reach some suspected terrorists in remote places. Adding to their appeal is the same attraction that gives any other use of armed force an advantage over less kinetic tools of statecraft: it brings direct, immediate, tangible results, in this case in the form of dead terrorists. More indirect and intangible are the negative effects, including resentment and radicalization stimulated by collateral damage from the operations. The asymmetry that favors more attention to the first effect than the second—even though the longer-term radicalizing impact may ultimately shape terrorist threats against the United States more than any number of bad guys the drones kill—probably already has pushed the drone strikes past a point of diminishing returns. The results have not been encouraging in, for example, Yemen, where the number of violent radicals has increased during the same period that drone strikes have, even before the effects of the current civil war there began to be felt.

THE MOST intense debates about the use of U.S. armed force are now centered on ISIS and its enclaves in Iraq and Syria, where the ISIS problem is superimposed on a complicated civil war in which a mélange of other opposition groups are also fighting against the Assad regime. Given that ISIS has supplanted Al Qaeda in American perceptions as the embodiment of international terrorism, discussion of what to do about ISIS is heavily weighed down by the baggage of 9/11 and the “war on terror.” Among the consequences are the presumption that military force is the primary tool to wage this “war” and an assumption that if ISIS is not dispatched in the Middle East then it is very likely to harm Americans. A tone of urgency has infused calls to destroy ISIS before it conducts a major terrorist attack in the United States.

More sober consideration would begin by recalling what should be one of leading lessons from the Iraq War: that ISIS did not exist before that war, and that the group (originally Al Qaeda in Iraq) came into existence as a direct result of the civil war that the U.S. invasion and overthrow of Saddam Hussein ignited. Careful consideration of the problem would note that ISIS, unlike the main Al Qaeda organization from which it openly split, rejected the “far enemy” strategy of Osama bin Laden and Ayman al-Zawahiri. ISIS has focused instead on building and defending its so-called caliphate (from the “near enemy”), with any terrorism against the West fulfilling the secondary goals of revenge, recruitment, diversion and deterrence.

Amid the sense of urgency about destroying ISIS’s enclave, little is said publicly about exactly what difference a group’s control of that kind of distant real estate makes for counterterrorism in the United States and the West. Even if some such real estate makes a difference, there is nothing sacred about the ground that ISIS has been occupying in Iraq and Syria. The broader history of Al Qaeda suggests that if there is going to be any base of operations for anti-Western terrorism, it is as likely to be somewhere on the periphery (such as Yemen), as in the group’s original sanctuary. More fundamental is the question of how a terrorist group’s control of any piece of territory affects the West. Experience indicates that such territorial control is neither necessary nor sufficient for significant international terrorist operations. Most of the preparation for 9/11 took place in apartments and flight schools in the West, and in cyberspace, rather than in the Afghan haven. Looking at counterterrorism through a war-tinted lens leads naturally to the equating of progress against ISIS with the movement of front lines on a map, as in conventional war.

What happens in ISIS’s caliphate does affect the group’s ability to inspire violent acts in the West. But these inspirational links may well be a matter of already radicalized individuals looking for a prominent brand in whose name they might commit violent acts they would have committed anyway. The mass shooting in San Bernardino, California in December 2015, which played a major role in stimulating the sense of urgency and alarm about possible ISIS-related attacks in the United States, is instructive. Although the shooters invoked the ISIS name, no evidence has emerged of any organizational connection with ISIS itself. Reportedly, the male half of the shooting pair had sought contact with different extremist groups, including Jabhat al-Nusra and al-Shabaab.

Of the two countries where ISIS has established its enclave, Iraq carries for Americans the baggage of the Iraq War and associated attitudes about sunk costs, but Syria is nonetheless the more complicated situation because of the uprising against the Assad regime. The revolt has regime-change juices flowing, stimulating an American itch to weigh in militarily, rather like what happened with Libya. This itch has spread to the Syrian regime itself, even though the Assads have ruled in Damascus for nearly half a century, so there would not seem to be a reason for urgency in toppling their regime. The impulse to use military force against the regime nonetheless has been strong, as suggested by how much American domestic opponents criticized the Obama administration for making use of a peaceful channel brokered by Russia to dispose of the Syrian regime’s chemical weapons rather than going to war over the issue.

Much of the urging to do more militarily in Syria constitutes inchoate expressions of toughness by politicians or of displeasure with the Syrian mess by others who assume this is yet another problem the United States ought to be able to solve if it applies its power. The relative priorities of confronting the Syrian regime and of dealing with ISIS are often left unclear, as are details of exactly what sort of additional military action the United States might take. The closest things to specificity have been mentions of a no-fly zone and calls for initiation of a ground war against ISIS. For the latter purpose, for example, McCain and former Republican presidential candidate Lindsey Graham have talked about deploying ten thousand U.S. combat troops each to Syria and Iraq.

The idea of a no-fly zone—embraced by, among others, Hillary Clinton—has the attraction of being responsive to the urge to apply more U.S. military force in Syria while sounding less costly than another quagmire on the ground. But although such a zone can be useful where (as with Iraqi Kurdistan in the past) a friendly and well-established authority on the ground could use protection from a hostile force with air power, that is not the situation in Syria. Left unanswered in most calls for a no-fly zone are questions about who controls the ground underneath the prohibited airspace and who will do the fighting to ensure the control stays the way America wants it. Moreover, even just the air component entails a much bigger military commitment—i.e., initiating direct hostilities with the Syrian regime—than those suggesting the idea seem to realize. (Given that ISIS has no air force, a no-fly zone would be useless against that group.) Enforcement of the zone would probably include attacks against Syrian air-defense capabilities and would entail significant risk of direct combat with Russian aircraft flying missions in support of the Syrian regime.

Proposals for U.S. ground operations against ISIS are based on the false premise that “taking out” the group with a quick assault on its positions would be the end of the task. It would not. It would mark the beginning of a new phase of the war characterized by guerrilla attacks, terrorism and other asymmetric operations. Chaos and instability left where the self-styled caliphate once stood would be a fertile garden for additional violent extremism, whether it bore the ISIS name or some other label. There would be no more justification for declaring “mission accomplished” after toppling the ISIS command structure than there was for declaring it in Iraq after toppling Saddam Hussein’s regime. Political scientists Stephen Biddle and Jacob Shapiro assess that taking and holding ISIS’s territory would require not ten or twenty thousand U.S. troops but instead one hundred thousand. In other words, it would be another large, costly and, perhaps, interminable counterinsurgency and nation-building effort.

FOR THE United States to plunge into the Syrian war would play into ISIS’s hands. It would confirm the group’s narratives about it leading Muslim defenses against a predatory West and about apocalypse between itself and the leader of the West. The inevitable collateral damage from increased lethal operations would foster the sort of resentment that aids terrorist recruitment.

Barack Obama, when pressed to do more militarily, has explained the situations in Syria and Iraq in terms that indicate he understands well the aforementioned costs and risks. In his last year in office, he has resisted the pressures to go beyond the approximately four thousand U.S. troops he has reinserted in Iraq, a very small ground presence in Syria and anti-ISIS air operations in both countries. His successor, however, is likely to be someone who will not only have more hawkish views but also, as a first-term president, be more easily moved by the urges and impulses that have pushed the United States into its state of perpetual warfare.

Those urges and impulses are deeply rooted in American history and, thus, in American habits of thinking. Occasionally, as after the Vietnam War, the sheer magnitude of the costs has led to a temporary departure from those habits.

Given the nature of the current debate, such a departure does not appear forthcoming. Quite the contrary. The United States appears destined, for reasons related to what makes it exceptional, to continue using military force beyond what serves its interests. It will take exceptional leadership to limit the resulting damage.

Paul R. Pillar is a contributing editor at the National Interest and the author most recently of Why America Misunderstands the World.

Image: U.S. Army soldiers in Al Muradia village, Iraq. Flickr/U.S. Army.