Despite its advertisement as a low-yield, lower-risk alternative to existing missile models, the recently tested B61-12 nuclear gravity bomb presents several risks that may in fact elevate the threat of nuclear use and encourage proliferation.

Late last year, the United States successfully completed testing of the newest addition to its nuclear arsenal — the B61-12 nuclear gravity bomb. Part of a $355 billion effort to modernize its increasingly outdated nuclear capability, the U.S. has developed the B61-12 to the tune of over $10.4 billion as the most adaptable, precise nuclear gravity missile on the planet.

Successful testing of the missile has now created a clear pathway for production engineering to begin in 2016, and with that, the United States is now poised to acquire 480 bombs total by the 2020-2024 period.

Washington argues that the development of an enhanced B61 gravity bomb is an important facet of the broader nuclear modernization efforts required to protect itself and its Western allies from threats like Russia and Iran. Other countries, especially non-nuclear states, underscore the hypocrisy of a nuclear modernization effort given President Obama’s stated commitment towards disarmament and nonproliferation.

In reality, both of these arguments have merit — though the debate is, in practice, fruitless. The United States will modernize its nuclear arsenal regardless of opposition, and the advent of the B61-12 brings with it a series of geopolitical opportunities and risks that are intrinsic to its own technical characteristics.

Enhanced Surety and Strategic Opportunity

The B61-12 presents a highly potent addition to the Pentagon’s nuclear cache.

As with all gravity bombs, the device will be configured to drop from stealth jets in free-fall over a given target — a deployment mechanism that has henceforth led to relative inaccuracy. However, the B61-12 avoids these traditional pitfalls due to a precision-guided tail kit modification that consumed the majority of the overall development cost.

This makes the new B61s the most precise nuclear gravity weapons ever conceived — providing the U.S. with an accuracy of within 30 meters.









Under the shell of a B61-12, unparalleled precision is combined with notable versatility. The bomb will be capable of serving as both a strategic and a tactical nuclear weapon — suitable for large area targets like cities as well as on the battlefield — and will boast a scalable yield between .3-50 kilotons.

In short, the B61-12 allows the U.S. and its NATO allies to strike targets with incredible precision and accuracy across a wide span of circumstances — in turn establishing a more controlled blast range. Together, these unique characteristics not only endow the United States with a more formidable nuclear capability, but also the key opportunity of lower radiation yields and, as a result, much fewer unintended casualties.











From the eyes of strategic adversaries like Iran and Russia, a U.S. nuclear deterrent less at risk of harming the innocent, allied, or otherwise untargeted is a U.S. nuclear arsenal less restrained and more realistically deployed. By removing a great deal of uncertainty from the equation, B61-12s will enhance the U.S. nuclear deterrent and create a greater incentive for opposing actors to think before moving against Washington’s interests.











Source: Federation of American Scientists

At the same time, B61-12s will lower security risks by increasing nuclear surety by three-fold.

First, the introduction of the new weapon between 2020 and 2024 will replace four classes of existing U.S. nuclear weapons and ultimately reduce the number of nuclear gravity bombs in Washington’s arsenal by just over 50%. A smaller arsenal is by nature easier to protect and therefore less at risk to both proliferation threats and nuclear accidents.

Second, these modernized B61s include enhanced safety features like greater explosive insensitivity and anti-sabotage mechanisms that make unintended or unsanctioned detonations significantly more difficult.

Third, risk is further reduced by the B61-12 considering that it replaces higher-yield weapons with lower-yield substitutes — a trade-off now afforded by greater accuracy. A lower yield innately decreases the severity of proliferation and accident risk.

Western nuclear powers like the United States are typically regarded as possessing a respectable degree of nuclear security over their arsenals — but security breaches at Belgian nuclear bases hosting current iterations of the B61 have proven that this reputation is in many ways undeserved. Greater nuclear surety is therefore an especially notable opportunity afforded by this latest modification.

Lower Nuclear Yield, Higher Nuclear Probability

Yet, in contradictory fashion, the same unique technical qualities that make the B61-12 a more accurate, secure, and effective U.S. nuclear deterrent also conjure implied risks with the potential to negate any positive impacts.

By significantly increasing accuracy and eroding the barriers to use previously presented by unintended casualties, the B61-12 does indeed increase the deterrent capability of the United States — but it also poses the contrary reality of an increased probability that nuclear weapons will actually be launched.

This concept of greater usability entirely forgoes the core assumption of deterrence theory, which asserts that credible nuclear deterrents are always present but never utilized. In short, B61-12s will broaden the range of circumstances that U.S. military strategists might reasonably consider employing nuclear weapons, a move which in turn would naturally create an immediate possibility of escalation towards full-fledged nuclear war.

In addition, the sheer expense and symbolism of creating a highly modernized, highly precise nuclear weapon like the B61-12 challenges the notions of nonproliferation and disarmament.

Washington’s pursuit of the B61-12 simultaneously legitimizes Russian vertical proliferation while potentially intimidating Beijing into accelerated arsenal growth. It also assures unofficial nuclear powers like Pakistan, India, and Israel that acquisition of low-yield nuclear weapons is an acceptable alternative to procuring high-yield strategic missiles.

Prior to official deployment between 2020 and 2024, it is difficult to tell with certainty whether the B61-12 will lower the U.S. nuclear threshold by enough of a margin to significantly alter the Pentagon’s strategic calculus. It is also unclear the extent to which the B61-12 Life Extension Program may encourage proliferation in other states.

For now, all that is certain are the technical improvements that the new B61s will afford to the U.S. nuclear capacity.