Erdogan’s Ambitions Go Beyond Syria. He Says He Wants Nuclear Weapons.

“Erdogan is playing to an anti-American domestic audience with his nuclear rhetoric, but is highly unlikely to pursue nuclear weapons,” said Jessica C. Varnum, an expert on Turkey at Middlebury’s James Martin Center for Nonproliferation Studies in Monterey, Calif. “There would be huge economic and reputational costs to Turkey, which would hurt the pocketbooks of Erdogan’s voters.”

“For Erdogan,” Ms. Varnum said, “that strikes me as a bridge too far.”

There is another element to this ambiguous atomic mix: The presence of roughly 50 American nuclear weapons, stored on Turkish soil. The United States had never openly acknowledged their existence, until Wednesday, when Mr. Trump did exactly that.

Asked about the safety of those weapons, kept in an American-controlled bunker at Incirlik Air Base, Mr. Trump said, “We’re confident, and we have a great air base there, a very powerful air base.”

But not everyone is so confident, because the air base belongs to the Turkish government. If relations with Turkey deteriorated, the American access to that base is not assured.

Turkey has been a base for American nuclear weapons for more than six decades. Initially, they were intended to deter the Soviet Union, and were famously a negotiating chip in defusing the 1962 Cuban Missile Crisis, when President John F. Kennedy secretly agreed to remove missiles from Turkey in return for Moscow doing the same in Cuba.

But tactical weapons have remained. Over the years, American officials have often expressed nervousness about the weapons, which have little to no strategic use versus Russia now, but have been part of a NATO strategy to keep regional players in check — and keep Turkey from feeling the need for a bomb of its own.