In diplomacy, always leave your adversary an honorable avenue of retreat.

Fifty years ago this October, to resolve a Cuban missile crisis that had brought us to the brink of nuclear war, JFK did that.

He conveyed to Nikita Khrushchev, secretly, that if the Soviet Union pulled its nuclear missiles out of Cuba, the United States would soon after pull its Jupiter missiles out of Italy and Turkey.

Is the United States willing to allow Iran an honorable avenue of retreat, if it halts enrichment of uranium to 20 percent and permits intrusive inspections of all its nuclear facilities? Or are U.S. sanctions designed to bring about not a negotiated settlement of the nuclear issue, but regime change, the fall of the Islamic Republic and its replacement by a more pliable regime?

If the latter is the case, we are likely headed for war with Iran, even as our refusal to negotiate with Tokyo, whose oil we cut off in the summer of 1941, led to Pearl Harbor.

What would cause anyone to believe Iran is willing to negotiate?

There are the fatwas by the ayatollahs against nuclear weapons and the consensus by 16 U.S. intelligence agencies in 2007, reaffirmed in 2011, that Iran has no nuclear weapons program.

Even the Israelis have lately concluded that the Americans are right.

Nor has the United States or Israel discovered any site devoted to the building of nuclear weapons. The deep-underground facility at Fordow is enriching uranium to 20 percent. There are no reports of any enrichment to 90 percent, which is weapons grade.

Iranian President Mahmoud Ahmadinejad has lately mocked the idea of Iran building a bomb in the face of a U.S. commitment to go to war to prevent it:

“Let’s even imagine that we have an atomic weapon, a nuclear weapon. What would we do with it? What intelligent person would fight 5,000 American bombs with one bomb?”

Ahmadinejad did not mention that Israel has 200 to 300 nuclear weapons. He did not need to. The same logic applies.

And Tehran seems to be signaling it is ready for a deal.