OVER THE next ten to twenty years, the erosion of American nuclear superiority will have major ramifications for the global balance of power. It will place new constraints on our freedom of action and lead our friends and foes alike to doubt the credibility of all instruments of U.S. power. As a result, decades-old alliance structures may fracture amid a drift toward multipolarity. Leadership from Tokyo to Riyadh to Seoul may find new incentives to develop their own deterrents as the relative power of states like Russia and China increases. With our extended-deterrent power lost, the international system will change-and not in Washington's favor. But this scenario is preventable if policy makers cast away the illusion of safety and act quickly to correct a trend which has plagued Washington for nearly two decades.

The giant has feet of clay. Though today the United States is widely seen to be dominant in almost every aspect of military power, and the expectation is that it will remain so, an examination of its nuclear forces and infrastructure reveals that its position is far from assured. The critical question is not whether the United States enjoys a strategic advantage in the area of nuclear forces presently, but rather what the forces and nuclear infrastructures of the United States and its competitors will look like ten or twenty years from now. If Washington does not modernize, Russia could acquire a nuclear advantage within the next two decades.

The United States faces major problems in the maintenance of its nuclear forces and infrastructure. It is the only nuclear country that cannot manufacture a new nuclear weapon because of a self-imposed moratorium, which has halted the modernization of warheads and delivery systems alike. Even though Washington possesses an unparalleled capacity to modernize, Congress has failed to fund any new nuclear initiatives. Strategic forces have been continually overlooked by Department of Defense and air-force leadership because of a constant de-emphasis on the role of nuclear weapons within the halls of the Pentagon. This began after the cold war and has only been accelerated by doctrinal shifts outlined in documents like the 2001 Nuclear Posture Review, which argued that advanced conventional munitions could supplant nuclear forces in certain instances. But the problem of leadership on this issue extends across the Potomac to Capitol Hill. Members of Congress on both sides of the aisle simply fail to understand the ongoing strategic military competition in which the United States finds itself, where the major powers are continuously jockeying for advantage.

What was true during the cold war remains so: nuclear weapons are a tremendous source of power in the international system. Conventional military superiority will almost always be trumped by nuclear superiority. But the United States cannot continue to live off of nuclear capital accumulated during the cold war. We must combat the false impression that the U.S. nuclear enterprise is still strong and will remain so into the future. It is decaying in almost every respect, from the nuclear warheads themselves to the missiles that deliver them to the scientists that build them. These weaknesses in the nuclear arsenal will cause U.S. strategic forces to fail to meet future mission requirements.

That is good news for our competitors, who have not taken a "nuclear holiday." Though Beijing's rise should be watched closely by Washington, our biggest rival in the nuclear realm is not China. While the United States is letting its arsenal degenerate, its nuclear peer-Russia-is constantly improving its nuclear forces and infrastructure. The overwhelming military superiority of the United States cannot simply be assumed to last into the future; it's time for a concerted effort by policy makers in Washington to invest in needed capabilities. The repeated failures to properly fund U.S. nuclear-modernization efforts are both shortsighted and dangerous.

As the United States' nuclear capabilities and skills atrophy, a time will soon come when the United States is weaker in relative strategic power than Russia. The impact on national security will affect every ally from Europe to Asia. The substantial benefits the United States derives from its nuclear umbrella will be no more. Thanks to these weaknesses, our allies and enemies will doubt the credibility of the U.S. extended deterrent, giving other powers freer reign to threaten U.S. interests abroad. Aggression against the United States will become more likely because Washington's ability to respond to such force will be diminished. And advancement of U.S. interests against foes who-for the first time in history-may be better armed with nuclear weapons than the United States will be hindered. Other nuclear states will continue to modernize their arsenals and maintain robust nuclear infrastructures if the credibility of the U.S. strategic deterrent is doubted. Moreover, states now covered by U.S. extended-deterrent commitments, such as Japan, Saudi Arabia and South Korea, would likely acquire nuclear forces. And current allies may align themselves with emerging nuclear powers. The most dangerous threat to the United States is the hubris and shortsightedness of those who believe that American military dominance is guaranteed.

TODAY, THE most modern nuclear-weapons capabilities belong not to the United States but to Russia. If unchecked, Russia's modernization will ensure that leadership in the realm of strategic forces will pass from Washington to Moscow. This is not to argue that all is well with Russia's nuclear capabilities. Other recent analyses have argued that Russia's strategic arsenal has so deteriorated that the country no longer has a survivable second-strike capability. Or even that Moscow's nuclear-weapons capabilities can't rival those of Washington. Russian forces may have deteriorated since the cold war, and they may not yet be modernized completely. But Moscow has begun to revamp its arsenal, and the United States has not kept pace. These competing analyses are incomplete because they examine the current strategic nuclear balance, but fail to analyze how Washington's nuclear paralysis will affect U.S. strategy and strategic commitments over the next two decades.

One conclusion is inescapable: the Russian strategic hiatus of the 1990s ended when Vladimir Putin succeeded Boris Yeltsin. Since 1999, the Russians have conducted annual strategic exercises for all to see, the scale of which matches what was typical during the cold war, and far beyond what the United States has done. Indicating, too, how important, Russian exercises also involve the highest echelons of the government. In August 2005, in the course of a major exercise, then-President Vladimir Putin actually flew in a bomber that launched four land-attack cruise missiles. The Russian leadership has made the modernization of its strategic nuclear weapons a priority; Putin was its greatest supporter and it is unlikely that his handpicked successor, Dmitri Medvedev, will change course.

These efforts are remarkable, standing in stark contrast to the stasis and even decay of U.S. strategic forces. Buoyed by its vast energy resources, Russia's economy has grown over the past decade, creating the revenue base needed to modernize its military.

Major nuclear states organize their nuclear forces into three parts, or a triad-bombers, submarine-launched ballistic missiles (SLBMs) and intercontinental ballistic missiles (ICBMs). Moscow's new doctrine calls for updating each leg of the triad. The country is developing new strategic and tactical nuclear weapons, as well as radically lowering the nuclear threshold (the conditions under which Russia will employ nuclear forces). All of these weapons could be used in a first strike against Russia's enemies.

A hallmark of Russia's strength has always been its capacity to act on the continent. Bombers help Moscow do just that. Although bombers have never been as important to Russia's nuclear-weapons program as they have been to the American one, they are now a higher priority. Russia has a strategic-bomber modernization policy, which is fully in accord with its broader strategic-modernization goals. As with its bomber fleet, submarines have never been equal to the Russian ICBM force. But there is significant modernization to this leg as well with its new Bulava SLBMs, which offer a higher degree of survivability than ICBMs. Eventually, this could enable Russia to negate the U.S. Navy's long-held advantage in this realm.

But just as with the Soviet Union, the strength of Russian strategic nuclear forces lies with the ICBMs. They allow Russia to exercise its strength far beyond its borders, holding at risk countervalue targets like cities and counterforce targets like nuclear arsenals throughout the United States. Accordingly, the modernization program stresses these weapons. Russia has developed the silo-based SS-27, and is creating a road-mobile derivative of it, enhancing Moscow's second-strike capability. In addition, Russia tested a new ICBM, the RS-24. It has not yet been given a NATO designation, but will eventually replace the old SS-18 and SS-19 ICBMs.

More alarming still are reports that Russia is working on a new liquid-fueled ICBM which would far outclass U.S. missiles. Also in the realm of potential weapons, the Russians have discussed the development of a hypersonic glide vehicle that would reach distant continents quickly and be able to penetrate U.S. missile defenses. Russia is even developing a new long-range cruise missile. The United States canceled its equivalent in 2007.

The Russians are modernizing their low-yield nuclear weapons as well, which can be used for tactical or strategic purposes such as holding at-risk or attacking high-value leadership targets. Moscow is developing a precision, low-yield nuclear weapon and a "clean" nuclear earth penetrator designed to destroy deeply buried targets like government bunkers, while the U.S. Congress canceled the equivalent U.S. program. By maintaining a robust portfolio of tactical and strategic nuclear capabilities, Moscow is able to enjoy more flexibility to make and back up their nuclear threats.

The Russians are also strongly interested in electromagnetic-pulse (EMP) weapons, and are suspected of having a robust capability to threaten one of the United States' well-known weaknesses: its dependency on insufficiently hardened electronics for its military and key civilian sectors. An EMP attack against a major urban center in the United States would be catastrophic. It would destroy the fabric of American society and bring cities and many governmental functions to an abrupt halt. It would have profound implications for the economy, politics and personal security, on a scale never before witnessed in the United States.

Russia enjoys the most robust nuclear infrastructure in the world. As a result, Moscow should be recognized as the world leader in the ability to design and produce nuclear weapons. It has the world's largest nuclear-weapons-production complex, with two plants for nuclear-weapons assembly and one plant for plutonium and uranium pit production. Russia has admitted the ability to disassemble two thousand warheads a year, which equals the technical capability to produce about the same number of warheads. The United States, on the other hand, has not developed or produced a new warhead since 1989. Russia also has nuclear-testing facilities that are able to be used for nuclear tests with minimal preparation, and Moscow has admitted to conducting a robust program of subcritical tests that produce a small yield. So Russia's leadership can certify the reliability of their strategic systems through actual nuclear testing rather than relying on technical extrapolations, which are less reliable.

Russia will continue to produce the most advanced nuclear forces in the world not simply because of its technical capacity but because of its commitment to the maintenance of this tremendous source of strategic power. Nuclear weapons and strategic strike capabilities will remain the highest force-maintenance and force-procurement priority of the Russian Federation for decades to come. Unfortunately, the opposite is true for the United States.

AS RUSSIA expands its nuclear forces like gangbusters, the United States moves at a snail's pace. Washington faces two major strategic weaknesses: its ICBM force and its nuclear-weapons infrastructure. If these problems are not rectified, they will affect U.S. strategic forces' ability to deter other powers around the world. There are no "quick fixes" here given the lengthy timeline for the design, which may easily be ten years from conception through production to actual deployment. Accordingly, the strategic vulnerabilities of the United States must be confronted immediately, if the United States is to maintain its strategic position.

In the 1990s, the United States started its strategic-nuclear holiday, and began to reduce its nuclear forces and infrastructure and the attention which policy makers and the military paid to nuclear weapons. To meet the grand-strategic goals of the United States, including credible extended-deterrence commitments to allies like Japan well into the future, U.S. strategic forces must be modernized.

Washington's neglect of its strategic forces is shocking. There are no efforts to develop or produce new nuclear weapons, and no new ICBMs or SLBMs are under development. B-2 production has halted, and no U.S. bombers are on alert. Many strategic and tactical nuclear-weapons programs have been canceled. U.S. Army, Marines and Navy surface and air components are out of the nuclear-weapons business. The number of NATO substrategic nuclear weapons in Europe and NATO nuclear-delivery systems have gone from eleven to one, over an 85 percent reduction, and are no longer maintained on alert. This means that the nuclear umbrella the United States has held over our European allies has some huge holes. Should NATO face a major crisis with Iran or Russia, Washington would rue the day these weapons were withdrawn.

The first step to reverse the decline is to modernize the ICBM force. In the post-cold-war period, the ICBM force continues to make major contributions to the U.S. strategic deterrent. ICBMs possess a relatively large payload capacity, and are survivable against first strikes launched by any of Washington's potential opponents. Because of this, they complicate and discourage an adversary's counterforce attack options. Thus, ICBMs still fulfill a traditional cold-war mission of deterrence against peer or near-peer adversaries. However, this will change in the future if the United States does not modernize its ICBM force to address modernizations undertaken by the Russians and Chinese.

Drastic reductions in the size of the ICBM force will raise doubts about the capabilities of the United States. The ICBM force is robust now, but will not be in the future. However, as with every aspect of the U.S. strategic infrastructure, knowledge is at risk thanks to an aging workforce: the United States has a "critical skills" gap that is only widening.

The transmission of such hard-earned knowledge is critical for contractors and subcontractors alike. The ICBM community has recognized the need for skills management as an asset equal to any component of the missile. The human-capital element of modernization cannot be understated. It requires not only an investment in weapons systems but an investment in people-namely the scientists, engineers and military personnel who ensure the safety and security of this crucial source of U.S. power.

This problem affects all components of U.S. strategic systems. Research-and-development scientists and engineers, command-and-control of strategic forces, the ICBM, SLBM and bomber industrial base, and members of the nuclear-weapons design and production community in the United States all face this challenge. But no other nuclear country does, since all others are modernizing their strategic forces.

The aging workforce also hinders U.S. strategic forces' ability to gauge the effects of nuclear weapons on strategic systems. Many of the requirements for EMP hardening have been reduced in the wake of the cold war due to the perceived reduction in threat. This would have been unthinkable during the cold war, when the EMP threat, which could destroy any unprotected electrical equipment and cause massive system failures, was seen as a potential Achilles' heel for U.S. strategic forces.

Today, U.S. strategic forces may have EMP vulnerabilities that "snuck" into the design of new systems or subsystems because radiation hardening and survivability protection was ignored or could not be funded due to the added expense. These are real vulnerabilities that a U.S. adversary like Russia or China can exploit. The vulnerabilities will only become greater if they are not addressed immediately, because many of the people who developed EMP expertise during the cold war are no longer part of the workforce.

Even the nuclear warheads of the United States are problematic, since ensuring the reliability of the U.S. strategic arsenal will be quite a challenge. The last underground nuclear test conducted by the United States was in 1992. So the nuclear-weapons labs are faced with the problem of ensuring reliability of weapons without certain proof they work.

Attempts at revitalizing the nuclear infrastructure have been stymied by Congress, which consistently reduced and more recently zeroed out funding for the Reliable Replacement Warhead (RRW) program. The RRW program is critical because the weapons that comprise the backbone of U.S. strategic forces were designed during the cold war, and do not properly address the requirements of the United States in the post-cold-war period.

Finding a replacement for the W-76 warhead is particularly important because it accounts for about a third of the U.S. arsenal and, with modifications to its design, comprises the totality of the British arsenal. The W-76's replacement is called the Reliable Replacement Warhead-1 (RRW-1), and is designed to be safer, cheaper and more secure while improving longevity. New military capabilities were not incorporated in the design, but new safety features were.

The RRW-1 and subsequent designs were intended to exercise the creative abilities of the weapons designers, engineers and others involved in the design, production and certification of nuclear weapons. Whether it is building submarines or nuclear weapons, much of the knowledge about how to design and build the complex system is conveyed personally, as are solutions to problems encountered in design, production or deployment. The "graybeards" among the military, civil service and industry are retiring, and if their knowledge is not passed on to a new generation, then it will be lost-damaging the safety and reliability of the U.S. nuclear arsenal. Despite the RRW-1's great advantages, Congress refuses to fund it. In Washington, opposition to modernizing the United States' strategic deterrent has been bipartisan: nuclear weapons are largely considered to be unnecessary relics of the cold war by many on Capitol Hill.

THE UNITED States clearly faces substantial problems in its strategic-force posture. Worse, other nuclear states-China, France, Great Britain, India, Israel, North Korea, Pakistan and Russia-have not taken a "nuclear holiday." As a result, the relative strategic balance between the United States and its near-peer competitors has changed, and not in Washington's favor.

In the post-cold-war world, though, the United States will continue to depend on its strategic nuclear forces to accomplish its grand-strategic goals. That will become increasingly difficult if the United States does not act now to redress the key vulnerabilities in its arsenal. While these vulnerabilities may not receive significant attention in the U.S. press, they are noticed by the allies and foes of the United States.

Some members of Congress, such as Representative David Hobson (R-OH), have called for a "time-out" on new nuclear initiatives. However, the reality is that there are no "time-outs" in international politics. The United States does not get to stop the clock in the realm of competition in strategic nuclear arms. All other nuclear countries are modernizing while the United States is not. If the United States ignores its lead in strategic systems, the lead will go away, and then recapturing it will be significantly more difficult due to the loss of infrastructure and knowledge.

The key vulnerabilities discussed must be addressed with urgency by the new administration and Congress. The first step toward solving these problems is to recognize the important role strategic forces continue to occupy for U.S. grand strategy, and the need to act to end the nuclear holiday.

Bradley A. Thayer is an associate professor of defense and strategic studies at Missouri State University. Thomas M. Skypek is a Washington-based defense analyst with Booz Allen Hamilton. The views expressed herein are exclusively those of the authors and do not represent those of the U.S. Department of Defense or any other organization.