Over the past week, with the 8 April ceasefire largely holding, the conflict between Iran and the U.S./Israel centred on the Strait of Hormuz. After a separate truce in Lebanon, concluded on 16 April, Iran briefly reopened the strait to commercial traffic, but only in coordination with Tehran, only along routes it controls and only for the duration of the ceasefire. U.S. President Donald Trump, meanwhile, insisted that the U.S. naval blockade of Iranian ports would remain in place until a broader settlement is reached. Despite Trump’s proclamations of diplomatic breakthroughs, de-escalation thus became a contest over who will set the terms of the post-war order, rather than a mutual move away from coercion.

In any case, the strait’s reopening quickly became another source of friction. Iranian authorities said control of the waterway had reverted to strict military management in light of the continued U.S. blockade; commercial vessels reported gunfire; and tracking showed a renewed pattern of aborted crossings and ships waiting in the Gulf. Washington, for its part, said its blockade had turned back dozens of ships, and then escalated further by striking and seizing an Iranian cargo vessel on 19 April, just as Tehran signalled that it would not return to talks while the blockade remained in place. Tehran has also threatened retaliation, raising the risk that the two sides could slide back into conflict just as a new round of diplomacy in Islamabad appears imminent.

The showdown in the strait at least temporarily overshadowed manifold other unresolved disputes. Various issues relating to Iran’s nuclear program remain contentious, by all appearances, as do questions about the lifting of U.S. sanctions and the provision of security guarantees in the form of a non-aggression pact. Sequencing, too, appears to be a major obstacle: Iran is unlikely to surrender its leverage – above all, its stockpile of highly enriched uranium – up front, absent U.S. guarantees of reciprocal sanctions relief. As for Lebanon, the ten-day ceasefire that began 16 April (after Iran insisted on it and the U.S. leaned heavily on Israel) reduced immediate pressure on Hizbollah and the government. So far, Israel has used the pause to bolster its deployment in southern Lebanon and deepen, rather than abandon, its buffer zone. 

Tehran’s strategy has been to convert the ceasefire into acknowledgement of its prerogatives, rather than merely a means of getting breathing space. When it reopened the Strait of Hormuz, Tehran did not say it was accepting the principle of free navigation, as the U.S. and others have demanded. Rather, it presented the move as an offer of managed passage subject to Iranian routing, inspection and authorisation. It tied the reopening to calm on all war fronts, including Lebanon. It also said U.S. coercion must ease before it will consider any further loosening of its restrictions. 

In so doing, Iran’s leadership aims to signal that that a diplomatic solution remains possible but only as part of an arrangement that preserves its agency and avoids the appearance of capitulation. This point is particularly important because the Islamic Republic’s core supporters, many of whom are ideologically driven, reject any hint of compromise. Pressure from this constituency reportedly led the parliamentary speaker, Mohammad Baqer Qalibaf, to appear on state television to justify the decision to negotiate with the U.S. as coming from a position of strength.

A felt need to project strength also lies behind Iran’s claims that it is building missile and drone launchers faster than before the war. It wants to convey that its battlefield losses are only temporary setbacks that will not hamper it should hostilities resume. By projecting combat readiness, it hopes to force its adversaries to reconsider their reliance on coercion to extract further concessions.

At the operational level, however, Iran’s posture is more ambivalent. Tehran appears to believe it retains sufficient leverage to keep disrupting shipping, thereby raising the global cost of continued deadlock. But at the same time, it needs an end to the war and extensive sanctions relief. U.S. and Israeli strikes have been devastating, and the U.S. blockade has compounded the impact on its shattered economy. This mix of domestic political and economic pressures helps explain seeming contradictions in the regime’s stance: it asserts its conditional openness to renewed talks, yet at least publicly it baulks at sending a delegation to Islamabad while the blockade remains in place and insists that Iran’s nuclear rights are non-negotiable. 

Washington’s posture remains hard to decipher, but it may be an attempt to reshape the conflict rather than either end or openly widen the war. President Trump remains subject to countervailing forces. Gas prices are rising at a time when many voters are identifying “affordability” as the most important issue in the November midterm elections. No doubt mindful of the political winds, some members of Trump’s Republican party in Congress are voicing fatigue as the war drags on, even if they have yet to impose constraints on the White House. The president himself often appears eager to find an off-ramp from what he hoped would be a short-lived military engagement, and his repeated declarations of victory have the air of wishful thinking. Meanwhile, more hawkish figures are urging Trump to finish the job, finding echoes in the president’s own vows to bomb Iranian bridges and power plants if the ceasefire falls apart. 

Trump and his administration are still pursuing a negotiated outcome, as evidenced by the planned return of a high-level U.S. delegation led by Vice President JD Vance to Islamabad for the second round of Pakistani-mediated talks with Iran, which has yet to confirm its attendance. But what undergirds diplomacy is the assumption that Iran can be compelled to make larger concessions via the application of heightened coercive power. The blockade is the clearest expression of that notion. Washington sees it as a way to increase the costs to Iran of failure to reach an agreement. The blockade adds a militarised component to the “maximum pressure” sanctions campaign that defined Trump’s first-term Iran policy and was revived during his second – and that the Treasury Department has stepped up through a series of efforts dubbed Operation Economic Fury.

The problem for Washington is that its tactics are sending confusing signals to Tehran, particularly in light of Trump’s unfounded assertions about the state of negotiations. By maintaining the blockade even after Iran briefly reopened the Strait of Hormuz to commercial traffic, the U.S. signalled that it regarded incremental Iranian de-escalation as insufficient. The seizure of an Iranian-flagged ship on 19 April highlighted this mixed messaging: it demonstrated resolve in enforcing U.S. sanctions, to which the ship’s cargo was subject, but simultaneously increased risks that the blockade could prompt renewed escalation culminating in renewed open conflict. Meantime, interdictions could create practical and legal challenges for the Trump administration in terms of the disposition of any seized vessel as well as its crew. It remains to be seen whether the U.S. will limit its interdictions to sanctioned Iranian vessels or will seek to stop, board and seize third-party vessels travelling to or from Iranian ports.

Trump’s repeated threats to attack Iranian bridges and power plants only further muddy the picture. Arguably intended to deter Iranian ceasefire violations and to compel greater Iranian flexibility in talks, they could have the opposite effect of narrowing Tehran’s manoeuvring room, making it far more difficult for the regime to make concessions without appearing to be bowing to pressure.

Israel’s conduct during the week suggests a desire to preserve the option of escalation even if diplomacy on the U.S.-Iran track proceeds. On the Iranian file, Israeli leaders continued to define success in maximalist terms, emphasising the elimination of Iran’s ability to rebuild key nuclear and missile capabilities. That position creates inherent friction with any U.S. approach built around an interim or sequenced and narrower deal. Israel would accept a diplomatic outcome that constrains Iran more tightly than the current military campaign has done, especially if sanctions relief is minimal. It is far less comfortable with diplomacy that ends the war but leaves Iran with residual strategic capacity or gives it a substantial economic reprieve.

Hostilities in Lebanon offered Israel a way to sustain pressure on Iran, via its regional network, without causing a rupture in U.S.-Iranian negotiations. The ten-day ceasefire announced on 16 April mostly quieted the guns, but Israel quickly used the pause to consolidate a buffer zone inside southern Lebanon and, for the first time, publish a map of its new deployment line. Strategically, this move matters because it could suggest that Israel is seeking to make its wartime territorial gains at least quasi-permanent. Even when fighting slows, in other words, Israel is resisting a simple reversion to the status quo ante.

Gulf Arab states remain caught between concerns that are no easier to reconcile than before. On one hand, they want the war to stop and are cognisant of the Trump administration’s desire to find an off-ramp. On the other, they do not want the terms of de-escalation to validate Iranian dominance over regional trade routes or confirm a pattern of selective U.S. disengagement. What changed in the past week is that the truce in Lebanon and the brief reopening of the Strait of Hormuz gave Gulf states a glimpse of how quickly economic and military pressures might ease if diplomacy were to gain traction. 

The opening soon narrowed again, but the indications of diplomacy’s potential rewards help explain why some Gulf states are backing mediation efforts. At their third ministerial meeting, Saudi Arabia, Egypt, Türkiye and Pakistan used a forum in Antalya, Türkiye, held on 18 April, to advance what may become a regional track that would aim to put a U.S.-Iranian resolution on the most durable possible footing. Oman and Qatar have likewise continued to push for a negotiated outcome. While Washington and some in the Gulf see the U.S. blockade as giving the U.S. leverage in negotiations, it harms the Gulf states’ economies and exposes these countries to further military spillover. Gulf states are therefore hoping that talks can lead to an outcome in which neither the blockade nor Iran’s muscle flexing in the strait hardens into a new regional order.

As it stands, there are three main scenarios for the days ahead: a U.S.-Iran agreement on a memorandum of understanding that sketches the broad framework for a deal that could resolve the conflict; a mutual decision to extend the fragile ceasefire while diplomatic efforts continue (which could happen with or without a meeting in Islamabad); and a collapse of mediated efforts resulting in a resumption of hostilities. 

As concerns the most positive scenario, it cannot be ruled out that U.S. and Iranian negotiators will return to Islamabad and agree upon a memorandum of understanding that settles the conflict, if not now, then in the future. But the parties would need to close significant gaps on the issues they see as most critical: the future of navigation in the Strait of Hormuz, Iran’s nuclear program and sanctions. The most consequential question for the coming week may therefore be whether the two-week ceasefire can be extended or, conversely, maritime confrontation outpaces diplomatic progress. The U.S. vessel seizure on 19 April crossed a threshold, demonstrating Washington’s willingness to be aggressive with the blockade even before the ceasefire ends. Tehran will now come under pressure to respond in a way that preserves deterrence without triggering a naval clash, or a wider resumption of hostilities, that it may not yet want. 

If the U.S. continues interdictions, and Iran keeps challenging the blockade for its own vessels while resuming fire upon others, risks of a military exchange involving patrol craft, drones or warning fire directed at commercial traffic will inevitably rise. Any such incident is unlikely to remain confined to the maritime domain for long, and the situation could very quickly escalate in dangerous ways. Already, Iran has signalled that attacks on its civilian infrastructure would prompt retaliation against Gulf energy facilities (which might include Saudi Arabia’s pipeline that provides an alternative to the Gulf trade corridor) and desalination plants. It might also urge its Houthi allies in Yemen to shut down traffic in another vital waterway, the Bab al-Mandab, or press Hizbollah to fire more rockets at Israel. At the same time, if Washington eases enforcement of its blockade without securing visible Iranian concessions, it risks discrediting its military threats. All of which suggests increased odds of miscalculation: each side has reasons to probe the limits of coercion, and neither seems able to design a clear face-saving off-ramp.

Several indicators bear watching. First, will Iran confirm its participation in another Islamabad round and, if so, on what preconditions? Secondly, will the U.S. navy make additional interdictions of Iranian ships or will it quietly relax enforcement to avoid clashes? Thirdly, will commercial traffic in the strait resume in a predictable pattern or remain episodic and politically conditioned? Fourthly, will the Lebanon ceasefire move toward a more durable arrangement or will it be eroded by Israeli actions inside the new buffer zone? If these indicators all flash red, the state of the conflict will cease to be diplomacy backed by coercion and become coercion accompanied by stalled diplomacy. That would mark a shift back toward open hostilities, with wider regional consequences. Even if diplomacy continues, however, the core dilemmas that have undermined previous rounds remain, making a comprehensive agreement difficult to achieve.