President Donald Trump has wisely muted his boasts of ending the Ukraine war in a day. His peacemaking energies might be better diverted to another intractable conflict: the U.S. standoff with Iran.

Iran, the main U.S. adversary in the Middle East, is weaker than it’s been in decades. A high inflation rate, a plummeting currency, capital outflows and lack of investment have hollowed out the economy. A brutal crackdown on protesters has enraged ordinary citizens.

Most importantly, Israel has literally blown up Tehran’s strategy of using proxies such as Hamas and Hezbollah as a first line of defense. Israeli strikes have dismantled key air defenses, exposing critical installations to attack.

Some in Trump’s orbit argue that the U.S. and Israel should seize this opportunity to bomb Iranian nuclear facilities and possibly topple the regime. They’re correct that Iran has enough fissile material to make a dozen bombs already and growing incentive to weaponize it.

Yet the arguments against military action remain as strong as ever. A strike would be hugely complex and challenging. Even stripped of defenses, facilities buried deep underground will be hard to destroy. Any gains would be temporary, while an attack is as likely to spur Iranians to rally around the government as it is to overthrow it. Whatever regime emerges could well be even more radical and obdurate.

Some Iranian officials are signaling they’re open to negotiations. It’s at least worth exploring if a bargain can be struck that improves on the 2015 nuclear deal Trump abandoned during his first term.

To start, the administration should hash out a common position with allies in Asia, Europe and the Gulf, as well as Israel — both to present Tehran with a united front and to prevent any aggrieved parties from playing spoiler. At a minimum, any negotiations must address the full range of Iran’s destabilizing activities, including its nuclear and ballistic-missile programs and its support for regional proxies. This should be in Tehran’s interest as well: A weak agreement that can’t survive scrutiny in Congress is unlikely to last.

Nonetheless, persuading Iran to negotiate seriously may require additional pressure. Existing sanctions will need to be enforced far more rigorously; the U.S. can give China a chance to scale back purchases of Iranian oil and punish Chinese actors in the trade if it doesn’t. The European signatories to the 2015 deal should make clear they’re prepared to reimpose “snapback” sanctions — an option that expires in October — if Iran doesn’t slow its enrichment activities, resume full cooperation with nuclear inspectors and show swift progress in talks.

While Trump ought to avoid unnecessary threats, the regime should be in no doubt that military strikes remain an option. The Pentagon should conduct more joint exercises with Israel simulating an attack on hardened nuclear facilities and invest in research into new weapons that might make such an operation easier. Strategic leaks about internal deliberations and discussions with the Israelis could help concentrate minds in Tehran.

At the same time, the administration should present Iran with enticing alternatives, potentially including economic incentives and sanctions relief, in proportion to the scale and pace of Iran’s concessions.

Full normalization of ties would require an indefinite cap on enrichment, verifiable limits to Tehran’s missile program, and a cutoff of weapons and training for militia groups. Any agreement should be open-ended, without the sunset clauses that made the 2015 deal so controversial. And Trump should submit it for Senate approval, to ensure buy-in across the aisle.

If Iran seems unlikely to agree to any deal strong enough to last, U.S. leverage is also greater than it was during Trump’s first term. He shouldn’t wait to use it.