For Iran's nuclear program, a month is longer than it sounds

The furious debate over whether U.S. strikes obliterated Iran's nuclear program or only delayed its progress toward being able to build a nuclear weapon by a few months skips over a key component in the equation: Iran's political calculation.

- Jared Malsin & Laurence Norman

If Iran were to make the decision to build a nuclear weapon, it would be betting that it can complete the job and establish deterrence before the U.S. and Israel intervene—through military action, economic pressure or diplomacy—to stop it.

A longer timeline increases the risk of being spotted or struck again, which could dissuade Iran from taking such a gamble in the first place. So measured on the Iranian nuclear clock, a delay of a few months could translate into a lot longer than it sounds if it keeps Tehran from moving ahead.

"If they start their breakout effort, and it takes them three more months, that's a lot of time to respond. It gives you time to detect it. It gives you time to mount a response," said Michael Singh, managing director at the Washington Institute for Near East Policy and a former senior official at the National Security Council. "It's not nothing."

The 2015 international nuclear deal negotiated by the Obama administration, which granted Iran sanctions relief in exchange for limits on its nuclear program, was designed to keep Iran a year away from being able to produce enough fissile material for a nuclear weapon.

President Trump pulled the U.S. out of that agreement in his first term. Iran scaled up its nuclear work a year later and by May this year, it was producing enough fissile material for a nuclear weapon every month.

Before the war, the general assumption was it would take Iran a few months to make a crude weapon as powerful as the bomb dropped on Hiroshima and deliverable by truck or ship, and one to three years to make a warhead that could be fit atop a missile.

Some analysts are concerned the attacks by Israel and the U.S. may have convinced hard-liners in Tehran that the only way to preserve the regime is to make a run at developing nuclear weapons.