Based on the Obama Administration’s April Nuclear Posture Review, conventional weapons are poised to gain a more prominent role in the U.S. deterrence posture. Carnegie hosted a conference on conventional deterrence to explore conventional weapons’ increasing role in strategic deterrence and the implications for extended deterrence, arms control, and strategic stability.

The Role of Conventional Forces in U.S. Deterrence Strategy and War Planning

In the event’s first panel, Michael Gerson of the Center for Naval Analyses, Brad Roberts of the Department of Defense, and Victor Utgoff of the Institute for Defense Analyses addressed the potential and optimal roles for conventional weapons in U.S. deterrence policy. Carnegie’s James Acton moderated.

Nuclear deterrence generally focuses on preserving peace by relying on the threat of inflicting unacceptable punishment. Conventional deterrence rests on the very different logical of denial.

  • Denial: Conventional deterrence relies on denying an opponent a quick, low-cost victory, Gerson noted. He outlined the logic behind a conventional denial strategy:

    1. Adversaries seek fast, inexpensive victories. Long, costly wars ruin economies and jeopardize domestic support.

    2. Accordingly, conventional deterrence is based on preventing an opponent from achieving core objectives rapidly and cheaply.

    3. If an adversary seeks a quick victory and deterrence seeks to deny that, then the local balance of power is crucial. The deterring power needs to ensure its potential adversary does not believe itself to have a local military advantage. This suggests forward-deployed forces are singularly important to conventional deterrence, although the value of long-range strike forces should not be underestimated. Gerson noted that forward-deployed does not mean the troops or weapons already need to be in the theatre; they must, however, be able to be rapidly deployed.

  • Challenges for Denial: Roberts and Gerson stated that conventional deterrence has to overcome several challenges. Low-level attacks are particularly difficult to guard against effectively. Fait accompli attacks, which rely on the element of surprise to accomplish objectives swiftly, must be prevented. Other challenges include:

  • Local Anti-Access Capabilities: Such weapons, like Chinese anti-ship ballistic missiles, can deny potential opponents the ability to reliably deploy forces quickly.

  • Credibility: Potential opponents might be emboldened by the belief that they can undermine U.S. resolve by threatening that, should the United States interfere in their activities, they will drag the United States into a protracted, bloody war noted Roberts and Gerson.

  • Proliferation Risk: The development of extensive conventional capabilities by the U.S. risks leading potential adversaries to produce unconventional weapons to counter the perceived threat. In spite of this potential threat, Roberts emphasized that the United States remains committed to an extensive international presence to support its allies.

  • Regional Security Architectures: The administration’s strategy of focusing on security regionally and incorporating conventional forces into an overall deterrence strategy serves the broad roles of reassuring allies and ensuring they remain secure, argued Roberts.

A prominent concern about an increased role for conventional weapons is doubt that such weapons could be used against the full range of targets potentially relevant for deterrence. Utgoff offered an assessment of U.S. conventional capabilities and potential abilities to strike targets of interest:

  • Deeply Buried Hard Targets: Precision-delivered conventional penetrators armed with high explosives could close all known entrances to a deeply buried target, but the target itself could not be destroyed.

  • Dispersed WMD-Armed Mobile Missiles: Precision conventional weapons should be able to disable such missiles, provided sufficiently detailed knowledge about their location was available.

  • Air and Missile Bases in Reinforced Concrete: Precision-guided weapons with large payloads would be able to deal with such fortified targets.

  • Cities: If American cities were attacked with nuclear weapons, the US might want the ability to retaliate in kind. Though conventional weapons could be effective, delivering the necessary number of munitions could pose very significant logistical challenges.

Conventional Weapons, Extended Deterrence, and Assurance

In a second panel, Elaine Bunn of the National Defense University, Carnegie’s Detlef Waechter, and Fumihiko Yoshida of Asahi Shimbun and Princeton University discussed how increasing reliance on conventional weapons will affect the dynamics of extended deterrence. Elbridge Colby of the Center for Naval Analyses chaired the session.

  • Contradictory Tensions: Allies protected by extended deterrence often fear abandonment; they doubt that America would sacrifice its national interests for the welfare of an ally, Bunn said. Simultaneously, allies fear entrapment or entanglement in U.S. foreign policy maneuvers. Relying on the U.S. security umbrella requires allies to have great confidence in American judgment, Bunn said, which creates chronic tension in alliances.

  • Role for Conventional Weapons: Bunn emphasized that conventional capabilities have always played a role in extended deterrence. Only recently have conventional weapons been explicitly tied to nuclear postures. The panelists agreed that an increased reliance on conventional weapons in extended deterrence allows for more creatively deterring low-level attacks, and allows allies to play a more active role in their own security.

  • NATO: Waechter explained that NATO is currently re-evaluating its policies, deciding whether to return to its traditional deterrence role – deterring attacks on European territory –  or to adopt more of an expeditionary character. He suggested that strengthening and streamlining conventional capabilities will enable allies to undertake both roles.

  • Japan: As a country protected through extended deterrence, Japan is experiencing a number of tensions and discordant views surrounding assurance and disarmament, Yoshida said. Many in Japan are interested in seeing expanded security assurances from the United States and are carefully scrutinizing U.S.-China relations. Yoshida argued that increased Japanese participation in improving regional dynamics is imperative. Without strategic dialogue, he warned that an arms race could develop in the region. Presently, many in Japan see the advancing Chinese missiles as threatening Japan rather than the United States.

Conventional Weapons, Arms Control, and Strategic Stability

In a third panel, Stephen Pifer of the Brookings Institution, Carnegie Moscow’s Petr Topychkanov, and The Hudson Institute’s Chris Ford–who formerly served as principal deputy assistant secretary of State for arms control, nonproliferation, and disarmament verification and dismantlement under President George W. Bush–discussed international reactions to increasing U.S. interest in conventional capabilities. Jan Lodal, former principal deputy undersecretary of defense, chaired the panel.

Topychkanov and Pifer addressed some of the chief Russian concerns regarding increased U.S. interest in conventional weapons for strategic deterrence:

  • Russian Concerns: Russia’s military leaders are increasingly concerned about the U.S. development of advanced conventional weapons, Topychkanov explained. These concerns relate to both prompt systems (like ballistic missiles) and non-prompt systems (like cruise missiles). In particular, Russian experts have expressed concerns about the development of weapons they believe could make Russian intercontinental ballistic missiles vulnerable to a conventional strike.  Topychkanov emphasized the perspective among Russian theorists that capabilities endure, while relations can shift.

  • Future Negotiations: Enhanced conventional weapons would hinder joint NATO-U.S. negotiations with Russia on the withdrawal of tactical nuclear weapons from Europe and on ballistic missile defense cooperation, Topychkanov and Pifer agreed.

  • Alleviating Tension: To alleviate tensions with Russia, Topychkanov advocated a ban on basing U.S. aerial attack forces in Europe. Russia, he suggested, could adopt a similar ban, and agree not to base its forces in the territory of its CSTO and CIS allies. If U.S. SSGNs were based in the Pacific Ocean, most Russian ICBM bases would be outside of their range, reducing Russian vulnerability and concern.

Ford argued that several outstanding questions must be resolved before the United States proceeds with reducing its nuclear arsenal and increasing reliance on conventional weapons.

  • Lower Yields: Using nuclear weapons enables the destruction of a target whose position is not precisely known. A target’s coordinates must be more accurately determined before launching a successful conventional attack.  

  • Counterforce Targeting: Ford noted that relying on conventional weapons undermines U.S. counterforce targeting ability. Lodal disagreed, pointing out that targeting the entire Russian strategic arsenal is not a serious option, even with nuclear weapons. Ford argued that retaliatory, although not preemptive, strikes should always be possible and relying on conventional weapons would make them more difficult.

A reduced focus on nuclear weapons raises a number of strategic questions about military postures, alliance relations, and technological capabilities, the panelists concluded. Addressing these questions requires a clear understanding of what deterrence ought to achieve–and a recognition of its limits.