President Trump announced a complete U.S. blockade of Iranian ports starting Monday, his latest pressure tactic after direct talks with Iranian officials in Pakistan over the weekend failed to yield an agreement. The U.S. Navy will intercept ships paying Iran for safe passage through the Strait of Hormuz. "We think that numerous countries are going to be helping us with this also," Trump told Fox News on Sunday.

Early Monday, there were no volunteers. British Prime Minister Keir Starmer said his country would not support a blockade. Australia's Anthony Albanese said his government had not been asked to help and called for de-escalation instead. Spain's Defense Minister Margarita Robles said the blockade "makes no sense" and represented "another episode in the downward spiral the world has been dragged into."

The American-Israeli war on Iran, now in its seventh week, has scrambled global trade and roiled energy markets. Oil prices surged on Monday while stocks fell, suggesting investors don't expect the blockade to quickly fix the damage. Professor Ahmet Kasim Han of TED University said Trump may be overestimating how effective economic pain will be in changing Iran's position. "Iran is already hurting, and they have shown that they are willing to take more than a couple of hits," he said.