According to unofficial reports, the United States stores approximately 50 B61 nuclear bombs at Incirlik Air Force Base in southern Turkey. After the failed coup in Turkey in mid-July 2016, the government arrested several high-ranking officers from the base and cut power for nearly a week. In late July, Turkish citizens protested outside the base, calling for its closure, though Turkish officials have assured U.S. officials that the United States will retain access to Incirlik and other bases in Turkey. These events have sparked debate about the weapons' security and plans to continue storing them at Incirlik.
Throughout the Cold War, the United States deployed thousands of shorter-range nuclear weapons with U.S. forces in Europe, Japan, and South Korea, and on ships around the world. These weapons were intended to extend deterrence and defend allies in Europe and Asia. While most were withdrawn in the 1990s, the United States retains around 200 B61 bombs in Europe. These serve not only to deter potential aggressors, but also as an important element in NATO's cohesion. While all NATO nations (except France) participate in NATO's nuclear planning, some also store U.S. weapons on their soil and provide aircraft that could deliver them in a conflict. Incirlik is unique, however, in that Turkey neither maintains nuclear-capable aircraft nor permits the United States to deploy its own at the base. As a result, the United States or other NATO partners would fly aircraft into Incirlik to retrieve the weapons and employ them during a crisis.
In several recent documents, including the 2010 Strategic Concept and the 2012 Deterrence and Defense Posture Review, NATO reaffirmed that it would maintain an "appropriate mix of nuclear, conventional, and missile defense capabilities" to support deterrence and defense. The alliance rejected suggestions to remove U.S. nuclear weapons from Europe while pledging to seek "the conditions for further reductions" in cooperation with Russia. The 2016 Warsaw Summit Communique noted that "the circumstances in which NATO might have to use nuclear weapons are extremely remote" but stated that it would maintain the "capabilities and resolve" needed to respond with nuclear weapons if "the fundamental security of any of its members were to be threatened."
According to unclassified reports, U.S. B61 bombs are stored on racks in secure underground vaults, inside protective aircraft shelters. The shelters are within a heavily guarded security perimeter, with U.S. forces responsible for their security. Reports indicate that the security perimeter at Incirlik was upgraded in 2015, and includes double fencing, lighting, cameras, and intrusion detection devices. The bombs are reported to be 12 feet long and heavy. Even if someone gained access to the shelters and vaults, it would be difficult to move the bombs without proper equipment. The bombs are reportedly also equipped with Permissive Action Links (PALs), which prevent the arming and use of the weapons in the absence of an authorization code.
Most experts agree the bombs are generally secure from unauthorized use and that U.S. forces would likely thwart most attempts to access or damage the weapons. But experts note the base is not impenetrable, and the safety, storage, and use control features are designed to delay unauthorized intrusion, access, and use while security forces defeat the threat and restore control. Some have speculated that a determined actor, particularly one with inside assistance, might be able to access the vaults and eventually disable the PALs and, possibly, employ a weapon. At the same time, others note that, even if this scenario were possible, the perpetrators would have to achieve this goal while U.S. and NATO forces employed all means necessary, including deadly force, to recover the weapon. In other words, while one can imagine a scenario in which the weapons might be at risk, the probability of such a scenario succeeding is extremely low.
Most experts agree that the weapons at Incirlik are not, at this time, vulnerable to theft or loss of control. But many have questioned the wisdom of the continued deployment of U.S. nuclear weapons in Europe, in general, and in Turkey, in particular.
Between 2010, when NATO adopted its most recent Strategic Concept, and 2012, when it completed the Deterrence and Defense Posture Review, many analysts and experts suggested that NATO consider changes to its nuclear posture, allowing for the possible withdrawal of U.S. nuclear weapons from Europe. They argued that this change would not only address concerns about the safety and security of the weapons, but might also spur Russian cooperation, leading to improved transparency and possible reductions in Russian nonstrategic nuclear weapons. Others, however, disputed this conclusion, arguing that the withdrawal of U.S. weapons from Europe could weaken NATO's security, upset the nuclear sharing arrangements, and undermine confidence in the U.S. commitment to the alliance. These concerns were particularly pronounced for some of the new NATO nations in Eastern Europe, due to their proximity to Russia.
While the failed coup in Turkey has reopened that discussion, it has also stimulated a more narrow debate about whether the United States should move the weapons out of Incirlik, given both the ongoing political uncertainties in Turkey, including the evolving state of U.S.-Turkish relations, and the base's proximity to territory controlled by ISIS. For example, the United States could consider moving the weapons to other NATO nations with bases equipped with the vaults needed to store B61 bombs and aircraft that could deliver the weapons in a crisis. However, this move might not only raise concerns about the U.S. commitment to Turkey's defense, but would also require the approval of the new host government. This discussion may continue in the coming months, particularly if the Turkish government restricts access or operations at Incirlik. The issue has implications for overall U.S./NATO-Turkey cooperation, as referenced in CRS Insight IN10533, Turkey: Failed Coup and Implications for U.S. Policy, by [author name scrubbed].