President Donald Trump has once again postponed the deadline for reaching an agreement with Iran, this time by another ten days, to April 6. He has warned that if Tehran refuses to accept at least some of the 15 points proposed by his administration, Iran will be turned into a “hell on earth.” But each time the deadline is pushed back, the credibility of that threat weakens. For that reason, it is hard to see why the Iranians would now feel compelled to give ground.

There is also a deeper issue: Iran does not trust Trump. He tore up the Joint Comprehensive Plan of Action negotiated under President Obama. In June 2025, the 12-day war and the US-Israeli bombing of Iranian nuclear facilities took place in the middle of negotiations. In February, another attack on Iran occurred while talks were under way in Oman. From Tehran’s perspective, neither Trump’s word nor his signature can be relied upon. Under those conditions, the only strategy left is to impose enough pain to deter further action. That may mean prolonging the conflict until the US and its allies begin to feel the costs directly, potentially through an oil shock that sends prices soaring toward $200 a barrel.

If Washington understands this, its own logic may point toward further escalation. Iran will not be coerced by air strikes alone, and so the pressure to consider a ground operation grows. That may help explain why the US is building up its military presence in the region, with Marines and paratroopers reportedly expected to arrive in the coming days. On this reading, Trump’s repeated extensions are not signs of restraint so much as a way of buying time for forces and equipment to move into place.

The most obvious initial target would be Kharg Island, off Iran’s coast, where roughly 90 percent of the country’s oil exports are processed. The US could seek either to seize the facilities or to destroy them, striking a devastating blow to the Iranian economy. On paper, such an operation might appear manageable. The forces already being assembled could be enough to capture the island, even if serious casualties would likely follow.

But if the target is so obvious, why would Iran appear willing to let such an attack happen? The answer is that once a ground invasion begins, Tehran may already feel it has won the more important battle. The US would be stepping into a conflict that could quickly become a quagmire, costly to sustain and difficult to end.

Capturing Kharg Island is one thing. Holding it is another. The island lies only a short distance from the Iranian mainland and would remain well within range of the Revolutionary Guards’ missiles and drones. That means US forces stationed there would remain highly vulnerable. To reduce those risks, Washington would likely have to extend operations to the nearby Iranian coast. That would be a much larger undertaking, requiring more troops, more equipment, and far greater political commitment.

The challenge would not end there. Iran’s southern coastline is backed by the Zagros mountains, which give defending forces a major strategic advantage. Any effort to push inland would therefore become vastly more complex. What begins as an operation involving 5,000 to 7,000 troops could quickly expand into one requiring tens of thousands, or more.

From there, two main scenarios present themselves. In the first, the US eventually prevails, reaches Tehran, and topples the regime. But even that apparent success would come at an extraordinary cost. The operation could require hundreds of thousands of troops, trillions of dollars, and many thousands of casualties. In Iraq, George W. Bush’s coalition deployed around 300,000 troops and reached Baghdad within weeks. Iran would be a far larger, more difficult, and more demanding campaign. And even if regime change were achieved, the US would then face the burden of stabilising and governing the aftermath, potentially for decades. Leaving Iran in chaos would not be a viable option, as it would create an even deeper and more enduring source of regional instability. In that case, Washington might achieve what it wants, but not what it actually needs: a sustainable peace.

The second scenario is worse. The US could become trapped in a prolonged war of attrition, unable to reach Tehran or decisively remove the regime even after years of fighting and heavy losses. This would be the Vietnam scenario: a grinding, open-ended conflict that drains lives, money, and political capital without delivering victory. Such an outcome could become more likely if Russia or China chose to support Iran, whether directly or indirectly.

There is, in theory, a third possibility: that the US could achieve its objectives in a matter of months and at relatively limited cost. That outcome cannot be dismissed entirely. But it is difficult to regard it as realistic.

Seen in this light, Iran may be inviting one of the first two scenarios to unfold because neither offers a genuine victory for the US, let alone for Trump. This is why the repeated postponements matter. They suggest not strength, but hesitation. By delaying, Trump may be searching for an off-ramp before events lock him into a conflict he cannot control. The question is why Iran should offer him one when it believes time and escalation are working in its favour. All of this suggests that, in the near term, further escalation remains the most likely outcome.