U.S. Military Advantages and the Future of Nuclear Arms Control

Protest against nuclear weapons of mass destruction

The United States and Russia are implementing the New START Treaty, which requires that each side reduce to no more than 1550 deployed strategic warheads on no more than 700 deployed strategic missiles and bombers by 2018. The Obama administration would like to go further. Doing so, however, will require that Washington address several related issues, first and foremost missile defense. Solutions on these issues are possible, if both Washington and Moscow are prepared to engage seriously.

In June 2013 in Berlin, President Obama proposed to reduce New START’s limit of 1550 deployed strategic warheads by one-third and called for “bold” though unspecified reductions in non-strategic nuclear weapons (NSNW, also referred to as tactical nuclear weapons). Administration officials have said privately that Washington also is prepared to make corresponding reductions in deployed strategic missiles and bombers, as well as in New START’s limit on deployed and non-deployed missile launchers and bombers.

Following New START’s entry into force in 2011, U.S. officials expressed interest in negotiating an agreement that would constrain all U.S. and Russian nuclear weapons – strategic and non-strategic, deployed and non-deployed – under a single aggregate limit, perhaps with a sublimit on deployed strategic warheads. That would mean that, for the first time, all U.S. and Russian nuclear weapons would be on the negotiating table.

U.S. officials have shown less interest in such an approach recently, believing that such a “big” treaty would require considerable time to negotiate and likely would not be finished during the remainder of President Obama’s time in office. (It would be best to submit a treaty to the Senate for consideration before 2016, a presidential election year, so such a treaty would need to be finished in 2015.) U.S. officials now talk of taking different approaches to limits on different classes of nuclear arms. While the U.S. government seeks to reduce the numerical limits in New START, it is consulting with NATO on transparency and confidence-building measures regarding non-strategic nuclear weapons, which may be necessary first steps for engaging Russia on reducing such weapons.

For its part, Moscow has shown little enthusiasm for nuclear reductions beyond those required by New START and has said that other questions must be addressed in conjunction with a discussion of further reductions. These include: differences over missile defense, treatment of conventional prompt global strike systems, multilateralization of the nuclear arms reduction process, limitations on conventional forces in Europe and outer space. With regard to NSNW, Russian officials have said that all such weapons should be withdrawn to national territory – which would require the removal of some 200 U.S. nuclear bombs from Europe – as a precondition for any negotiation. U.S. officials reject the precondition but allow the possibility that this could be the outcome of a negotiated agreement.

The manner in which Moscow has drawn these linkages reflects Russian concerns about U.S. advantages in these areas, which the Russians say could undercut the balance in strategic nuclear forces established by New START. Some question Russia’s general readiness for further reductions and believe that the purpose of the linkages may be to give Moscow a pretext not to reduce beyond New START, at least for the present.

While U.S. military forces have developed certain leads in missile defense and high-tech conventional weapons, it is important not to overstate U.S. military superiority or advantages. The American military has just disengaged from a long effort in Iraq, is drawing down from an even lengthier campaign in Afghanistan, faces significant budget cuts, and must recapitalize its military equipment holdings. Most U.S. allies in Europe likewise face significant budget reductions, while the Russian military has embarked on a major modernization program.

That said, Washington appears to understand that, if it wishes to make progress on further nuclear arms reductions, it must address at least some of the linked questions posed by Moscow. It should be possible to do so. The rest of this paper will explore how.

Missile Defense

The underlying Russian concern about missile defense stems from the offense-defense interrelationship, which is recognized in the preamble of the New START Treaty. Moscow worries that, should the United States deploy larger numbers of more sophisticated and effective missile interceptors, that could undermine the strategic offensive nuclear balance. This concern is entirely understandable, in principle.

The Russians have since 2011 asked for a legally-binding guarantee – i.e., a treaty – that U.S. missile defenses would not be directed against Russian strategic forces. They seek to have the guarantee accompanied by “objective criteria,” by which they mean limits on the numbers, velocities and locations of missile interceptors. That would amount to a revival of the 1972 Anti-Ballistic Missile Treaty, from which the George W. Bush administration withdrew in 2002.

There is no way at present that Senate Republicans would consent to ratification of such a treaty. Unfortunately, the debate over missile defense in Congress currently is driven as much by ideology as it is by an appreciation of strategic questions or an understanding of the actual capabilities of individual missile defense systems. While Russian officials correctly note that this is an “American” problem, it precludes the kind of treaty on missile defense that Moscow seeks.

A legally-binding treaty on missile defenses may at some future point be necessary and appropriate if the numbers of strategic ballistic missile warheads and ballistic missile warhead interceptors are more proximate. But that is not the case now and will not be for the foreseeable future. The gap between strategic offense and strategic defense is huge.

The New START Treaty requires that the United States and Russia each have no more than 1550 deployed strategic warheads as of February 2018. By that date, the U.S. military will deploy – at most – 44 interceptors with a velocity capable of engaging a strategic warhead, about two-thirds the number of strategic missile interceptors that the Russian military currently deploys around Moscow. Forty-four or 68 interceptors, even if each had a 100 percent probability of killing an incoming warhead (which they do not), would still pose little threat to the strategic offensive forces of the other side.

Although the U.S. decision in March 2013 to cancel phase 4 of the European phased adaptive approach to missile defense was driven by cost and technology issues rather than Russia considerations, it nonetheless ended the aspect of that missile defense system of greatest concern to Moscow: SM-3 interceptor missiles with velocities capable of engaging strategic ballistic missile warheads. In April, U.S. officials proposed a bilateral executive agreement requiring the sides to provide transparency about current and planned missile defense programs. Such transparency would allow each side to determine whether there was any serious threat pending to its strategic offensive forces and provide sufficient warning time to react were such a missile defense threat to emerge.

Russian officials understand that a legally-binding treaty now is not possible. If Moscow dropped its demand for a legal guarantee and limits – while preserving the right to return to the question later in the event of a serious narrowing of the gap between offense and defense – the path to a resolution of missile defense concerns would be open.

Moreover, the path would also be open for a cooperative NATO-Russia missile defense system of Europe, which NATO and Russian leaders agreed to explore in November 2010. Washington and Moscow could build on ideas already discussed in both Track I (Pentagon-Ministry of Defense) and Track II channels for how independent NATO and Russian missile defense systems – neither side would be prepared, at least initially, to work under the command of the other – would interact. These ideas include:

  • transparency regarding current and planned missile defenses;
  • joint missile defense exercises (the United States, NATO and Russia already have experience of such exercises);
  • a jointly-manned NATO-Russia data fusion center to receive early warning and tracking data from U.S., NATO and Russian radars and other sensors, combine it, and send the enhanced product back to the NATO and Russian missile defense commands; and
  • a jointly-manned NATO-Russia planning and operations center to exchange views regarding possible ballistic missile threats to Europe, likely attack scenarios, and plans and rules of engagement for operating missile defenses.

These ideas could go a long way to addressing Russian concerns about missile defense … if Moscow wants to find a solution to this issue as opposed to keeping it alive in order to have a pretext to avoid discussion of further nuclear arms reductions.

Conventional Prompt Global Strike

The Russians have expressed concern about the increasing accuracy and lethality of long-range conventionally-armed systems on the U.S. side, worrying that such systems could attack targets, including strategic targets in Russia, that previously would have required nuclear weapons. The question of conventional prompt global strike can be broken down into three parts, each of which can be addressed in a different way.

First, should either the United States or Russia consider putting conventional warheads atop strategic ballistic missiles, those warheads would be captured by the New START Treaty. The 1550 limit on deployed strategic warheads makes no distinction between nuclear warheads and conventional warheads. A side choosing to deploy a conventional warhead on an intercontinental ballistic missile (ICBM) or submarine-launched ballistic missile (SLBM) would have to deploy one less nuclear warhead.

Second, hypersonic glide vehicles, although accelerated on a ballistic missile, do not fly a ballistic trajectory and thus would not be captured by New START. The U.S. military seeks to develop a hypersonic glide vehicle capable of delivering a conventional warhead to a range of 6000 miles within one hour of launch. Were the Pentagon to make serious progress on such a vehicle, it would be developing a weapon that nearly replicates the capability of an ICBM. In that case, New START’s Bilateral Consultative Commission provides a venue to discuss such systems, their impact on the viability of the treaty, and how to deal with such systems. (It should be noted that the Russian military is exploring hypersonic glide vehicles as well.)

The United States sees the requirement for hypersonic glide vehicles as limited. It is described as a “niche” capability, measured in terms of a few dozen warheads at most. A hypersonic glide vehicle would be a very expensive way to deliver a conventional payload to a target at long distance, running in the tens or hundreds of millions of dollars per vehicle. Limited defense budgets would constrain the number of hypersonic glide vehicles that the United States might deploy, if they could be perfected. Given the small number, one solution would be to put them under the New START warhead limit, in the same way that the Obama administration accepted placing conventional warheads on ICBMs or SLBMs under the 1550 limit.

Third, conventionally-armed air- and sea-launched cruise missiles, according to some Russian analysts, pose a threat to strategic nuclear forces, including ICBM silos. It would be difficult for one side to move sufficient numbers of cruise missile platforms to the vicinity of the other without detection, which would give the other strategic warning. The Russians appear to have a particular concern about conventionally-armed sea-launched cruise missiles on submarines, including the four former Ohio-class ballistic missile submarines that have been converted to carry sea-launched cruise missiles, fearing that submarines might approach Russian coasts undetected.

Beyond that, U.S. and Russian military analysts appear to have different assessments of the capabilities of conventionally-armed cruise missiles against certain targets, particularly hardened ICBM silos. Russian analysts express concern that U.S. cruise missiles could effectively attack ICBM silos, while the U.S. military doubts that conventionally-armed cruise missiles would have a high probability of killing a silo.

Conventionally-armed cruise missiles represent a key part of U.S. force projection capabilities, and it is difficult to see the U.S. military accepting significant limits on them (the same may be true for the Russian military, which also seeks to develop new cruise missile capabilities). But Washington and Moscow might constitute a military-to-military working group to explore the capabilities of conventionally-armed cruise missiles and their implications for the overall strategic nuclear balance.

Multilateralization of the Nuclear Arms Reduction Process

Washington and Moscow between them hold more than 90 percent of the world’s nuclear weapons, and this will remain the case even after New START’s limits take full effect in 2018. The United States and Russia thus have primary responsibility to lead on nuclear arms reductions. But the process cannot forever remain solely a U.S.-Russian enterprise. That said, the two nuclear superpowers hold a large numerical advantage over third countries: estimates put the U.S. and Russian nuclear arsenals each at around 4500 total nuclear warheads, compared to 300 for the largest third-country nuclear force. It is unlikely that third countries will be prepared at this point to engage in or accept negotiated reductions on their much smaller nuclear forces.

Discussions are underway among the UN Security Council Permanent Five on how they should meet their obligations under the Non-Proliferation Treaty (NPT). Washington and Moscow could discuss a joint strategy for encouraging the other P5 states to become more involved in the nuclear arms control process. For example, those states could provide transparency regarding their total warhead numbers. Going further, they might offer unilateral political commitments not to increase their nuclear weapons numbers as long as the United States and Russia are reducing their nuclear warhead levels. The approaching 2015 NPT review conference might provide a venue for mobilizing diplomatic efforts by non-nuclear weapons states to encourage Britain, France and China to take at least some steps.

One consideration for Washington and Moscow is that many Chinese and some French nuclear weapons systems are not “strategic” in the sense of the New START Treaty. Nor are the nuclear weapons systems of other third countries “strategic.” This is an additional reason for the United States and Russia to engage on NSNW: it will be difficult to ask third countries to constrain their NSNW if U.S. and Russian NSNW are not limited.

Conventional Forces in Europe

Russia suspended its observation of the 1990 Conventional Armed Forces in Europe (CFE) Treaty in 2008, complaining that NATO had not moved to ratify and bring the 1999 Adapted CFE Treaty into force. After a failed effort to restore Russian observance of the CFE Treaty, NATO countries suspended certain of their CFE obligations as regards Russia in 2011. At this point, it is difficult to see how the CFE Treaty might be revived, let alone how the Adapted CFE Treaty might be brought into force.

The CFE Treaty (as did its successor) limited five categories of treaty-limited equipment (TLE): main battle tanks, armored personnel carriers, artillery, attack helicopters and combat aircraft. Most adherents to the treaty, including NATO member-states and Russia, are well below the limits provided in the CFE Treaty or those provided in the Adapted CFE Treaty. For example, in 2013 the United States withdrew the last of its main battle tanks from Europe. (Whether CFE’s TLE categories are the right measure of modern combat power in an era of new technologies such as drones is another question.)

With the defense budgets of most NATO countries in significant decline, TLE numbers are likely to decrease further on the NATO side. While Russia is increasing its defense budget and has launched a major military modernization effort, that program appears to be going slower than planned. It will be some time before the Russian military restores capabilities that pose a serious threat to NATO.

Although the CFE Treaty is for all practical purposes dead, it achieved its principal objective. Neither NATO nor Russia appear capable now or for the foreseeable future of mounting a major surprise ground offensive and/or seizing and holding large swatches of the other’s territory.

It thus may make more sense for NATO, Russia and other European countries to focus their efforts on confidence- and security-building measures (CSBMs) regarding conventional forces: notifications of exercises and major military movements; observations of exercises; and inspections of military forces. In doing so, the sides could build on the Vienna Document on CSBMs and the Open Skies Treaty regime, to which NATO countries and Russia largely continue to adhere.

Such measures could strengthen confidence regarding knowledge of the military capabilities and intentions of other countries, particularly as regards the ability to conduct a large-scale surprise attack. Progress on such CSBMs might provide a foundation for a later return to the question of limits of specific categories of conventional weapons.

Outer Space

Moscow has for many years decried the possibility of the militarization of space and called for negotiation of a treaty to prevent it. It is not clear, however, what kinds of space-based systems drive the Russian concern. The U.S. military currently has no serious plans to deploy strike systems in space.

The United States nevertheless makes heavy use of space in its military operations, including for command and control, communications, surveillance, reconnaissance and targeting. The Defense Department historically has been concerned that any agreement to limit military activities in space could infringe on these sorts of capabilities.

The European Union has suggested an international code of conduct for space operations, and the U.S. government is open to the idea. It may offer a way forward. Although considerably less sweeping than the Russian proposal, it would provide a starting point for discussion of outer space issues.


Unfortunately, the various linkages drawn by the Russians have knotted up the process of further nuclear arms reductions. As noted above, there are approaches to resolve or address the issues that Moscow has linked to nuclear cuts, which might create a path to unravel the knot. The U.S. government has engaged on missile defense and would likely be prepared to explore approaches to address some of the other questions. It would be important, however, to have an indication that, were Washington to do so, Moscow would be prepared to deal seriously on further reductions in nuclear arms.