Can diplomacy deter Iranian nuclear ambitions a second time?

It has the feel of high-pressure tournament chess, the players competing not just against each other, but the unforgiving tick of the clock. Only the Middle East’s current preoccupation is no game; it’s an international political face-off with major security implications for the region and beyond.

At issue is whether the Islamic Republic of Iran will complete its decadeslong quest to build a nuclear bomb – a security challenge the new administration in Washington is hoping to forestall in return for lifting the “maximum pressure” sanctions that former President Donald Trump put in place.

The reason why tensions have ratcheted up in recent days? Deeply discouraging signals about this U.S. strategy from both Iran and from Israel, Tehran’s most powerful regional rival.

The Iranians have so far rejected the idea of any quick diplomatic fix. They’re accelerating production of the material needed for a weapon. Israel, meanwhile, has taken the extraordinary step of saying publicly that it is updating plans for military action, and has reiterated its determination not to let Iran become a nuclear-weapons state.

The main problem, however, is the ticking of the clock.

Iran is now estimated by U.S. officials to be a few months away from “breakout point,” the moment at which it will have amassed enough weapons-grade fissile material for a bomb.

Mr. Biden’s foreign policy and security team is seeking urgently to stop the clock, giving Washington time to put together a diplomatic solution addressing concerns and objections on all sides. The two-stage package that Secretary of State Antony Blinken and National Security Adviser Jake Sullivan are working on will take many months, at the very least, to achieve.

That package would first revive the 2015 Iran nuclear deal under which Tehran accepted a series of limits and verification mechanisms on its nuclear program in return for relief from earlier sanctions. The Iranians were complying, according to the International Atomic Energy Agency, until Mr. Trump pulled the United States out of the agreement in May 2018 and imposed new sanctions.

In stage two, the administration would attempt something Iran has long rejected, but which Israel and many members of the U.S. Congress would like to see. That would be a wider agreement, going beyond Iran’s nuclear program, to set limits also on its ballistic missile program and to constrain its military interventions across the Arab world, from Yemen to Iraq, Syria, and Lebanon on the Mediterranean.

But the focus now is stage one, reviving the 2015 agreement, and even that is running into obstacles.

On the major substance, the Americans and Iranians actually agree: Iran’s return to the 2015 limits (which it began ignoring one year after the U.S. pulled out of the deal) in exchange for Mr. Biden lifting the Trump sanctions.

But Washington wants Iran verifiably to halt and reverse its violations of the 2015 limits – on the enrichment of uranium and addition of new centrifuges – before it lifts the sanctions. Iran is insisting that, since it was Washington and not Tehran that abandoned the agreement, the Americans should rejoin and end the sanctions first.

Israeli Prime Minister Benjamin Netanyahu, for his part, has long opposed even the 2015 agreement as an insufficient guarantee against Iran going nuclear. Israel will, at a bare minimum, want to see evidence that the Iranians are reversing course before the Americans ease sanctions pressure.

And there are domestic political pressures to reckon with as well. Israelis are going to the polls in March, and the Iranians in June. In both countries, the prevailing political winds favor the foreign-policy hard-liners.

The Biden administration will hope cooler heads in both Iran and Israel prevail.

After all, the Iranian economy is suffering very badly from the Trump sanctions; and military action is not something Israel can embark on lightly.

Beyond the political costs of a military strike, including the certain opposition of Washington, Israel’s most important ally, it would also raise practical issues. Iran has dispersed its nuclear facilities and sought to protect them against bomb or missile attacks. And while a targeted attack could delay the Iranians’ breakout point, Iran could well retaliate through its Hezbollah militia allies in southern Lebanon, whose missile batteries are capable of hitting Israel’s main towns and cities.

In his first remarks as secretary of state, Mr. Blinken last week made no reference to Iranian or Israeli reticence about U.S. plans, simply reiterating that if Iran was verified as having returned to “full compliance” with the 2015 agreement, the U.S. would do the same. That, he made clear, was going to take time.

But in a television interview this week, he pointed to the more immediate challenge.

He warned that if the Iran nuclear deal remained a dead letter, with Washington outside and Tehran disregarding its provisions, Iran could come “within weeks” of breakout point.

In other words, the clock is ticking.