Trump is bombing Iran again and blundering again. He has no grasp of his enemy | Sina Toossi

And so to war. Again. After a ceasefire and a hiatus, Donald Trump is now into the second day of a new phase of bombing Iran, with the US military claiming to have struck 170 Iranian targets in the past 48 hours.

This is no surprise. Speaking at the Nato summit in Ankara this week, Donald Trump said he believes the US-Iran memorandum of understanding is “over”. He described Iran’s leaders as “evil, sick people” and threatened renewed military action and even a new blockade of Iranian ports, while also leaving the door open to further negotiations.

Those remarks followed a fresh round of US strikes on southern Iran after Tehran attacked commercial vessels transiting the southern part of the strait of Hormuz, outside the shipping corridor it had designated, and were also the precursor for today’s attacks. Late on Wednesday, explosions were reported across a further three locations in Iran. Conflict will only escalate from here. On Truth Social, the president wrote: “This is in retribution for yesterday’s bombing of ships by Iran. If it happens again, it will get much worse!”

Yet the memorandum’s collapse did not begin this week. It began unravelling almost from the moment it was signed because of the central problem that has haunted US-Iran diplomacy for decades: there is no credible basis for trust. Tehran had little reason to believe Washington would deliver durable sanctions relief, abandon its longstanding strategy of coercion and regime change, or refrain from returning to those same policies once Iran had surrendered its principal sources of leverage. That is why the struggle over Hormuz has become the memorandum’s defining issue rather than a peripheral dispute.

On paper, the memorandum offers a pathway to de-escalation. Its logic is sequential: shipping through Hormuz would resume under Iranian “arrangements”, the US blockade on Iran would be lifted, Tehran would receive an oil waiver and access to portions of its frozen assets, threats would cease, and the war in Lebanon would end. Together, these steps were meant to create a minimum basis of confidence after the war and open the door to negotiations over Iran’s nuclear program.

But that logic depended on a fragile assumption: that Washington and Tehran would both treat partial implementation as a bridge toward a larger settlement rather than as an opportunity to preserve leverage while testing the other side’s resolve. In practice, neither side came to believe the other was honouring the commitments that mattered most.

From Tehran’s perspective, Washington began violating key provisions immediately. The memorandum’s first clause, which called for an end to the war in Lebanon, was never fulfilled, with Israeli forces continuing operations and maintaining a presence in parts of the country. The US has also reportedly resisted releasing Iran’s frozen assets on the scale Tehran expected. Trump continued issuing military threats, including publicly threatening to kidnap Iranian negotiators during the first round of talks in Switzerland. Then, on 7 July, the US revoked Iran’s oil export waiver as Tehran was trying to consolidate control over shipping through Hormuz, not by permanently closing the strait, but by forcing vessels to transit through its designated northern route rather than the US-backed southern route.

Each side concluded that the other was pocketing concessions while withholding its own. Yet, this mutual distrust is not simply a product of recent events. It reflects decades of failed diplomacy.

Iranian policymakers have watched sanctions repeatedly imposed, partially lifted, and then reimposed across successive American administrations. From Tehran’s perspective, the central question is whether any US president can offer sanctions relief and make that relief durable. Much of the current US sanctions architecture is embedded in congressional legislation, leaving presidents to rely on renewable waivers that can be revoked with the stroke of a pen. Businesses and investors understand that reality, which is why even after the 2015 nuclear deal, sanctions relief failed to produce the level of investment, banking integration and return to economic stability Iran had expected. The larger consequence is that Washington has steadily eroded the credibility of sanctions relief itself. If economic relief is viewed as temporary and reversible, it loses much of its value as an incentive for lasting policy change. Tehran has drawn a stark conclusion: promises of future sanctions relief are simply too fragile to build the country’s long-term security and economic development upon.

That leverage is arguably even more consequential today than it was before the war. US strategic petroleum reserves remain substantially depleted, while global oil inventories remain tight as shipping through Hormuz has remained far below prewar levels. The result is far less cushion to absorb a prolonged disruption of the strait, increasing the risk of a much larger global energy shock.

Unlike trading away its nuclear program or other sources of leverage in exchange for sanctions relief that could prove temporary, Hormuz offers Tehran something fundamentally different: a guarantee that rests in its own hands. By routing commercial traffic through its designated corridor and potentially establishing a joint administration with maritime neighbour Oman capable of collecting transit fees, Iran would tie both its own prosperity and the costs of coercing it directly to the functioning of the global economy. Future US presidents could still abandon diplomacy. Congress could still tighten sanctions. But doing so would no longer be economically cost free.

This reflects a broader evolution in Tehran’s strategic thinking. Iran today possesses three principal forms of leverage against the US and Israel. The first is its military capabilities and regional alliance network, including its missile and drone forces, asymmetric naval assets, and partners such as Hezbollah, the Houthis and armed groups in Iraq. These can impose significant military costs, but even major battlefield successes are unlikely to fundamentally alter the balance against the combined military power of the US and Israel. The second is its nuclear program, long Tehran’s principal bargaining chip with Washington, which, despite extensive damage to its declared facilities, still leaves Iran with important options should it decide to dash for the bomb. Increasingly, however, it is the third source of leverage, control over the region’s strategic energy chokepoints, above all the strait of Hormuz, that has become indispensable.

That shift carries an important lesson for Washington. The question is not simply whether Iran is prepared to negotiate. It is whether the US can offer an arrangement Tehran believes will endure after it has surrendered its leverage. The memorandum never answered that question. It rested on assurances Iranian leaders regarded as reversible while asking them to dilute one of the few forms of leverage they considered durable. That does not make diplomacy impossible. But it does mean that agreements built mainly on promises of future sanctions relief are unlikely to survive.

If Washington fails to grasp how profoundly the war has reshaped Tehran’s strategic calculus, it will keep negotiating against assumptions that no longer exist, and keep producing agreements neither side truly believes the other will honour.

• Sina Toossi is a senior non-resident fellow at the Center for International Policy, where his work focuses on US-Iran relations, US policy toward the Middle East and nuclear issues