In recent weeks, the U.S. has been building up its military assets in the Middle East, including the largest deployment of airpower to the region since the 2003 invasion of Iraq. All these fighter-bombers, warships and missile batteries are there for one reason: to strong-arm Iran into making concessions on its nuclear program and military capabilities. If the effort fails, and conflict ensues, it will be the second armed confrontation between the U.S. and Iran in less than a year. But unlike during the brief U.S. intervention in Israel’s June 2025 war with Iran – which involved one-off bombings of three nuclear sites, followed quickly by a ceasefire – this time round Washington has flooded the region with armaments that could be used in a bigger, more sustained campaign. 

It remains unclear precisely what concessions the White House hopes to get out of its gunboat diplomacy. U.S. President Donald Trump has been shaking his fist at the Iranian authorities since Tehran’s bloody crackdown on mass protests at the start of the year. But while Iranian state forces have largely crushed the demonstrations, at least for now, the U.S. has continued to escalate its threats and, through its deployments, to bolster the means of backing them up. Trump has not sought congressional authorisation for fresh hostilities with Iran, but that means little at a time where U.S. constitutional requirements for war-making are routinely brushed aside.

Meanwhile, Washington’s demands have broadened, with some U.S. officials talking about containing Iran’s nuclear program and others talking about everything from defusing its ballistic missiles to scaling back its sponsorship of proxies elsewhere in the Middle East to destabilising the regime. Which of these are must-haves and which are just noise is obscure, even to Middle Eastern officials with a lot at stake should the region be unsettled by a confrontation, and it is not entirely clear if the White House knows its own bottom lines. Nor is it evident how much appetite Trump – whose record shows a preference for short wars he can easily spin as successes – has for the costly, messy conflict that could explode out of the current crisis.

But that is precisely what he may get if negotiators do not quickly find a way to make a deal. Just as the White House risks painting itself into a corner with its expensive, high-profile build-up and burgeoning demands, it is pushing Tehran into a corner where Iranian officials may see little to lose in answering any U.S. attack with a painful blow that would dim the U.S. aura of invincibility and cost Trump politically. Momentum appears to favour confrontation. Still, the diplomatic path is not yet entirely blocked, with a third and potentially decisive round of talks slated for 26 February. Both sides could advance their interests through a bargain in which Iran pledges to continue its current freeze on uranium enrichment, while details of a longer-term arrangements are hashed out, in return for a degree of sanctions relief. Such a deal could be supplemented by non-nuclear measures, such as limits on the range of Iranian missiles and their transfer to other state or non-state actors, as well as a non-aggression understanding between the parties. Such a deal would codify the status quo in some respects and break new ground in others. Together, these elements could give the parties what they need to step back from the brink. 

Much has changed since the White House and Tehran explored the contours of a new nuclear agreement in April and May 2025. Those negotiations proceeded in fits and starts, with their parameters limited to non-proliferation concerns and sanctions relief possibilities. The question of whether the gaps could have been closed was rendered moot by military action preceding a scheduled sixth round of talks. On 13 June, Israel launched a campaign against Iranian military and nuclear sites, as well as top military brass, in what became known as the twelve-day war. Toward the end, the U.S. joined in with Operation Midnight Hammer, striking nuclear targets and claiming (in Trump’s words) to have “obliterated” Tehran’s nuclear program. 

After the June war, a sense that immediate concerns had been tackled allowed all sides to stand down. For nearly eight months, Iran has by all appearances been meeting the zero-enrichment standard – the stated U.S. objective with respect to Tehran’s nuclear capability. Its apparent lack of activity is a function of the damage its enrichment facilities sustained as well as the high risk of detection were it to restart its program. Through the end of 2025, the parties seemed content with a no-agreement, no-war outcome. None had a strategic concern so pressing that it sought to resume talks. Nor was there an immediate reason to go back to war. 

But, beneath the surface, trouble continued to brew. For the U.S. and Israel, the war created uncertainty. Since June 2025, there have been no international inspections of the bombed sites. Moreover, despite Trump’s claims of obliteration, no one knows for sure how much the Islamic Republic may retain of its pre-war fissile material and advanced centrifuge stockpiles. Its plans for its nuclear program likewise remain unclear. Meanwhile, in Israel there is increasing concern about the rehabilitation of Iran’s ballistic missile program, as well as lingering worry about Tehran’s ability to support its weakened, but not vanquished, network of non-state allies in the “axis of resistance”.

As for Iran, the war morphed into increased economic coercion and diplomatic isolation, especially with the snapback of UN sanctions in September that the European signatories to the 2015 nuclear deal triggered. As public discontent grew, fear spread in Tehran that Israel and the U.S. were seeking to make Iran’s domestic fissures deep enough that a revolt would topple the regime. “They hoped that their military intervention in June would give rise to an upheaval”, a senior Iranian official told Crisis Group in October. “Now they are hoping that an upheaval could lead to a military intervention that would finish the job”. There were also concerns that Israel might see a window of opportunity to hit Iran again, taking advantage of defences still weakened by the June war and earlier Israeli bombings, in order to set back Iranian efforts to build more ballistic missiles. 

Then, in late December 2025, a new factor emerged. Economic turmoil and rapid devaluation of Iran’s currency sparked weeks of nationwide anti-regime protests. Peaceful at first, the protests grew in size and severity, prompting exiled opposition groups to call for mass mobilisation and President Trump to warn of U.S. intervention if the regime tried to suppress it. Trump’s admonitions did not stop Tehran, which brutally put down the unrest, massacring at least several thousand people, according to human rights groups, on 8-9 January of the new year. Some form of U.S. intervention seemed imminent in mid-January, but Trump held off, reportedly due to a combination of Arab lobbying and worries about Iranian retaliation against U.S. interests and allies. U.S. military leaders told the president they might be unable to stop a counterstrike.

To some extent, Washington’s decision to dispatch an armada to the Middle East can be seen as an effort to mitigate that risk as President Trump continues his campaign of coercive diplomacy, but the question of what he will do with the fleet should his administration fail to reach an agreement with Iran remains murky. The U.S. might be contemplating a limited strike to compel additional Iranian compromises; a decapitation campaign that would take out senior Iranian political and military leaders; a wider campaign targeting nuclear and missile capacity; or combined endeavour aimed at shaking the foundations of the Islamic Republic. Or it might all be a hugely expensive feint aimed at getting Tehran to acquiesce in some sort of deal. Whatever the case, the equipment is now in place for a sustained U.S. offensive.

For its part, Iran’s leadership, facing a convergence of internal pressures and external threats, warns that any attack will be met with a strong, direct response against U.S. forces. They suggest there will be little of the calibration the Islamic Republic showed after Operation Midnight Hammer, when it answered with a performative, telegraphed strike on a U.S. base in Qatar. Tehran is keen to demonstrate that it intends neither to fold nor to fall; rather, it is ready to fight, even if outgunned.

Both sides may well be posturing. Washington’s muscular deployments could be intended primarily as leverage to wrest maximal concessions out of Tehran at the table rather than as a prelude to war. U.S. military planners must be well aware of how much extensive fighting could cost, not only in terms of danger to U.S. forces and materiel but also in tax dollars. The twelve-day war of June 2025 cost Israel up to $12 billion, while depleting a quarter of the entire U.S. stock of THAAD interceptors – some 150 of them – which are worth $12 million apiece. Even within the military there is apprehension about the impact of sending so many U.S. assets to the Middle East on U.S. preparedness elsewhere.

Nor are Trump and his advisers blind to the political risks of launching another war in the region with the 2026 mid-term elections drawing near. Polls suggest a war with Iran will be highly unpopular, as U.S. voters are focused on economic issues and many (including in Trump’s own base) are surely wondering why a president elected in part as a non-interventionist shows such a predilection for military adventures.

As for Tehran’s vows to spill U.S. blood and turn any clash into a region-wide inferno, it is impossible to know whether these will survive contact with reality. The threats may be designed chiefly to dissuade a president wary of another open-ended Middle Eastern conflict, even as Iran grapples with its own vulnerabilities. The June 2025 war exposed major Iranian weaknesses in terms of air defences and intelligence failures that a U.S. or combined U.S.-Israeli operation could once again exploit, to even more damaging effect. Since Hamas’s attacks on 7 October 2023, the leadership in Tehran has chosen at every step to avoid an all-out escalation with the U.S. and Israel that would risk bringing about its own demise.

Unfortunately, bargaining by bluffing – if indeed that is what either side is trying to do – is intrinsically unstable, particularly when this much weaponry is involved. Measures meant to deter or coerce can just as easily provoke. Ample room exists for miscalculation or potentially even for spoilers to stage false-flag attacks that narrow leaders’ choices by pushing them to respond with force. In such a charged environment, the boundary between managed escalation and uncontrolled war is perilously thin – and often discernible only in hindsight. It is all too easy to imagine the sort of exchanges at sea that transpired in early February, with the U.S. downing an Iranian drone and Iranian forces attempting to seize a U.S. tanker, flaring into a bigger exchange without either side having decided to enter hostilities.

If the parties do in fact march over the precipice into war, it does not appear that either has a low‑cost military option. The U.S. could seek an initially limited operation to see if Iran runs up the white flag, but that gambit could well fail. With President Trump’s adoption of regime-change rhetoric, Tehran may see any coming confrontation as existential regardless of what the U.S. is trying to achieve. That, in turn, increases the likelihood that Tehran would retaliate in ways that could cost U.S. lives, pull in Israel, target other U.S. Middle Eastern partners, roil global markets, lay waste to critical infrastructure and risk reducing Iran to a shattered rump state. It is conceivable that U.S. fatalities and the economic backlash could severely damage Trump’s presidency and legacy – as the U.S. embassy hostage crisis hurt President Jimmy Carter’s and the Iraq war President George W. Bush’s.

It is probably these grim scenarios that leave Washington and Tehran open to the possibility of an agreement. After two rounds of engagement, in Muscat on 6 February and Geneva eleven days later, both sides and the Omani mediators all spoke of progress, albeit against the backdrop of low expectations. Notable, too, was the direct involvement of the International Atomic Energy Agency (IAEA), which would play a critical role in making sure Iran stays within any nuclear constraints. Its officials have engaged with both parties, as well as with intermediaries. But if the diplomatic track is to have any chance of success, there will have to be swift moves to capitalise on the setbacks to Iran’s nuclear program from the June 2025 war, clarify ambiguities about its enriched uranium stockpiles and sketch the outlines of its trajectory.

Iran would need to take two immediate steps to demonstrate its seriousness. First, it would have to provide IAEA inspectors access to its hitherto uninspected damaged enrichment facilities; and agree to dilute or ship out the nearly half-tonne of highly enriched uranium it held prior to the June 2025 war. Having set that baseline on transparency and accountability, Tehran would also need to agree to keep enrichment dormant, as it has apparently been since June. This freeze would hold until a longer-term, negotiated solution is in place: either a miniaturised and rigorously monitored enrichment program or a regional consortium. The suspension would not prejudice Iran’s notional “right” to enrich for peaceful purposes but could be presented by the White House as zero enrichment. In return, Tehran would expect a financial reprieve, in the form of access to assets or increased oil exports – potentially including as part of joint ventures with U.S. companies. 

Securing a suspension of enrichment and restoring the international safeguards to ensure verification would be a major achievement, but the U.S. is almost certain to insist on more. President Trump and his team have also raised a desire to curb Iran’s ballistic missile program and its proxy alliances. How to address missiles is likely to be the trickier issue. Iranian officials maintain that these projectiles are the country’s sole reliable deterrent and thus core to its national security. Still, the U.S. may be able to gain ground if it presses on two fronts.

First, it could ask Tehran to codify what has in the past been a voluntary range limit of 2,000km for its missiles, thereby ensuring that it will not develop arms capable of hitting U.S. territory (though, of course, regionally based U.S. assets would remain exposed and Israel within range). Secondly, the U.S. could seek a commitment from Iran not to transfer missiles or missile parts to Hizbollah, whose degraded but nevertheless potent arsenal in Lebanon remains a concern for Israel. This ban would also extend to the Houthis in Yemen. 

As for proxies, while the Islamic Republic is unlikely to openly abandon support for groups that threaten Israel or other regional states, Iran and the U.S. could lower the regional temperature by pledging to refrain from the threat or use of non-defensive force; not to support military action against any country in the region by any state or non-state actor; and to respect all nations’ sovereignty and territorial integrity. They could also affirm the importance of ensuring freedom of navigation and the protection of oil and gas shipments through vital waterways. Tehran could interpret such a non-aggression understanding as a guarantee from the U.S., and Washington could describe reciprocal Iranian pledges as a commitment that the Islamic Republic does not threaten Israel or other regional partners.

Reaching such a deal will be a tall order. First, resistance to talks in both Tehran and Washington is fierce. On the Iranian side, at least some senior officials see negotiations as either a U.S. ruse while the Pentagon puts additional military assets in place or a set-up whereby Washington will meet any concessions with further demands. Neither the 2025 negotiations nor the February talks have dealt with the details of sanctions relief or access to Iranian assets held abroad, which would be critical incentives for a government under profound economic duress and grappling with socio-political discontent; Iranian sceptics see this fact as a sign that negotiations are unserious. In the U.S., any plausible deal, even if delivering better returns than the 2015 agreement Trump repudiated in his first term, will almost certainly be met with reproach in some quarters for relaxing pressure on a long-time adversary that is economically weak, militarily outmatched and rattled by an uprising that exposed its brutality and lack of legitimacy. The question is whether Trump, on one hand, and Supreme Leader Ali Khamenei, on the other, will use the full extent of their influence to bring opponents of the deal to heel.

Secondly, there is a risk that both sides treat negotiations as a desultory box-ticking exercise and shy away from meaningful concessions, while looking forward to the start of hostilities as an opportunity to punch the hardest. Hardliners in Iran may be thinking that Tehran can best advance its interests by bloodying the nose of a U.S. president emboldened by the 3 January raid grabbing Venezuelan President Nicolás Maduro, while those in the U.S. may be looking to deliver a knockout blow to the Iranian leadership – either to secure its capitulation or to set in motion its collapse. Inside each system the question is whether the voices making these arguments can be countered by others pointing out the downside risks – in particular, that the exchange of short, sharp blows could easily escalate into something much bigger. 

If these obstacles can be surmounted, there may be just enough time for a determined diplomatic push to establish the parameters of an agreement, which could be fleshed out over time with the input from key regional powers that have the biggest stake in avoiding repeat crises. While settling on granular terms may not be possible given the deadlines Trump has imposed, tracing the broad contours may be sufficient for both sides to make the case that they have reached an advantageous deal, letting them avoid the military, economic and humanitarian costs that would be likely to follow failure. Gulf Arab and other Middle Eastern capitals that have much to lose from a regional escalation should continue pushing hard in this direction.

In nearly five decades of deep antagonism and occasional collaboration, the Islamic Republic and U.S. have never been so close to the precipice of a major conflict. Though the slide toward conflict appears increasingly hard to stop, the risks and uncertainties of a new war should focus minds on what could still avert it.