A little more than 100 miles from the territory held by the violent extremist group Islamic State, there is a little piece of Americana. It has an eight-lane swimming pool, a baseball diamond and housing tracts built on carefully manicured cul-de-sacs.
The Incirlik Air Force Base in Turkey has some other iconic American assets: several dozen B61 thermonuclear warheads.
The base has been a linchpin in NATO’s southern flank for more than a half century, the staging ground for important U.S. anti-terrorism missions and the fight against Islamic State.
But the failed military coup against Turkish President Recep Tayyip Erdogan last week has ratcheted up long-standing concerns about the military usefulness and security of the Incirlik armory, America’s largest foreign stockpile of nuclear weapons.
Security remains at the highest level, FPCON Delta. Electrical power was restored only Friday after a week-long blackout that strained living conditions at the base. The 3,000 U.S. service personnel stationed there have been ordered to remain inside the gates. Hundreds of military dependents were sent home months ago, amid fears of a terrorist attack.
The base was an operational center of the attempted coup. Its commander and his subordinates were arrested on suspicion of trying to overthrow the Turkish government, leaving junior officers in control. The developments have shocked U.S. military experts who say they demonstrate a worrying level of instability in Turkey’s military command close to the B61s.
Defense officials have never acknowledged the existence of these weapons on the base and refused this week at news briefings after the coup attempt to answer questions about them.
Lt. Col. Christopher Karns, an Air Force spokesman for U.S. Central Command in Qatar, said the electricity cutoff had forced water rationing and a slight reduction in bombing missions against Islamic State, also known as ISIS, but operations were returning to normal.
The weapons are located in underground vaults in a mile-long special security zone at the base, protected by an elite Air Force guard unit with attack dogs. The nearly 12-foot-long weapons have devices that are supposed to prevent an unauthorized detonation, but experts are sharply divided on the effectiveness of those controls.
Unlike the strategic weapons that the U.S. deploys in missile silos, submarines and intercontinental bombers, the weapons at Incirlik are tactical weapons that can be deployed at low altitude in the battlefield.
Any decision either about keeping or withdrawing the weapons in Turkey is fraught with political and military risks.
“Turkey was much more stable two years ago and ISIS did not stand where it is today,” said Philip Coyle, a former national security advisor for the Obama administration and a top Defense Department executive during the Clinton administration. “It’s all the more reason to pull the weapons out of Turkey.”
Wesley Clark, a retired four-star general and NATO’s supreme allied commander in the late 1990s, said he would not rule out a closer examination of NATO’s placement and policies on nuclear weapons, noting that he has “deep concerns” about Turkey’s situation. But he said that a wholesale withdrawal of the weapons is not necessary.
“They are very secure,” he said, adding that they could be extracted quickly if the situation deteriorated and that the electronic locks on the bombs would render them useless. “If you captured them, it would be like having a block of concrete.”
The B61s are broadly considered more of a political symbol of U.S. commitment to the NATO alliance than a military asset. The U.S. does not have aircraft at Incirlik qualified to deliver the weapons.
The B61s are the last U.S. tactical nuclear weapons based in Europe, originally placed there as a deterrent to a ground invasion by the Soviet Union. The bombs, an early 1960s design and the nation’s oldest model, have variable explosive power, anywhere from the equivalent of 300 tons of TNT to 170,000 tons of TNT.
In order for the weapons to actually be used, the U.S. would have to fly a squadron of aircraft into Incirlik to load the bombs, all of which would be observed by Russia and possibly make the base a target for a first strike. For this reason, the B-61 bombs will almost certainly never be used, said Aaron Stein, a Turkey analyst at the Atlantic Council, a think tank in Washington.
“The B61s inside Turkey are entirely symbolic, at this point,” he said. “But there’s no off-ramp of getting the weapons out of there.”
In some ways, the U.S. deployment of the weapons has become a hostage to history. It is unclear who has the authority to order their removal, though the final decision likely would go to the president. And how an emergency withdrawal would be handled is highly classified.
A sudden withdrawal of the weapons could have broad political ramifications for North Atlantic Treaty Organization, said Stephen Rademaker, assistant secretary of State for international security and nonproliferation during the George H.W. Bush administration.
“It would be a dramatic step,” Rademaker said, noting that a pullback based on concerns that Turkey is not stable enough for nuclear weapons could prompt a parallel question about whether the nation is trustworthy enough to be a NATO ally.
Turkey has the largest military force in NATO after the U.S. and has played a pivotal role in U.S. actions in the region dating back to a Lebanon deployment in the 1950s.
The U.S. maintains about 180 B61s in five European nations, while Russia has a tenfold advantage in tactical nuclear weapons.
U.S. nuclear weapons experts say the historic relationship with Turkey should not preclude a change in policy, based on rising security risks in the region.
“The weapons should be pulled back,” said Hans Kristensen, a nuclear weapons expert at the Federation of American Scientists. “They have been in excess of what is needed in Europe for the past two decades. And now we have this new situation. This is the U.S. nuclear base closest to a war zone. The country has a deeply fractured political and military system.”
Kristensen estimates that the security squadron based at Incirlik has about 130 people fully dedicated to defend the weapons, though no doubt other American personnel could be called on to defend the weapons. They are located in a security zone that is one mile long by a quarter-mile wide, bordered by double fences, motion detectors and night lighting.
The weapons have modernized safeguards, known as use controls and permissive action links. The electronic systems are supposed to disable the weapon if an unauthorized person attempts to arm the bombs. Sensors also prevent arming if expected altitude and velocity metrics are not met.
Robert Peurifoy, a retired Sandia National Laboratory engineer, warned against complacency, saying the use controls may only impede and delay a terrorist.
“Either you keep custody or you should expect a mushroom cloud,” said Peurifoy, who designed the first use controls on weapons based in Europe. “It might not be overnight but it won’t be too long.”
But many officials dismiss the likelihood of such a dire situation.
"Right now I have no concern about the safety and security of our forwardly deployed nuclear weapons," said Eric Edelman, former ambassador to Turkey.
But Edelman did express concern that in the days since the attempted coup, the Turkish military has been decapitated by government purges, leaving junior officers in charge. The Turkish military "is a much, much less capable partner for us," he added.
Times staff writer Tracy K. Wilkinson contributed to this report.