Donald Trump’s decision to go to war against Iran will be remembered as a grave strategic miscalculation – one that has reshaped the region in unintended and destabilising ways. With the ceasefire now extended indefinitely, we can see more clearly how the war has undermined the US’s standing in the world and failed to achieve its core objectives: it has neither brought about regime change in Tehran, nor forced Iran to submit to American demands. Far from it.

By inflicting economic pain far beyond the region and slowing the global economy, Iran has demonstrated that its grip over the strait of Hormuz constitutes its most potent deterrent – arguably more consequential than its now defunct nuclear programme. Control of the strait will be Tehran’s most powerful source of leverage in the years ahead.

And this strategy is not confined to Hormuz. Relying on its Houthi allies in Yemen, Iran’s Islamic Revolutionary Guard Corps (IRGC) also signalled its ability to threaten the Bab al-Mandab strait at the southern tip of the Red Sea – a choke point through which roughly 8% of global trade and a significant share of the world’s energy and chemical shipments pass. The prospect of disruption at both Hormuz and Bab al-Mandab would amount to a double shock to the global economy.

Against this backdrop, it is no surprise that the US’s Gulf allies have reacted with alarm. What most unsettles Gulf rulers is the prospect of a postwar Iran wielding control over Hormuz as a permanent lever of coercion – while the US appears, at best, an unreliable guarantor of their security. The Gulf states are scrambling to hedge against this new instability by building alternative security arrangements with regional powers such as Pakistan, Egypt and Turkey, while deepening ties with Europe, China and India.

Although the US/Israel-led war has weakened Iran economically and........

© The Guardian