The Strait of Hormuz: A war racing against time

After an Israeli missile strike killed Iran's Security Chief Ali Larijani, Tehran is vowing revenge. Meanwhile, US President Donald Trump is calling for international backup to force open the Strait of Hormuz, but allies are, so far, avoiding being drawn into the war. In a notable development, a Pakistani-flagged tanker is reported to be the first non-Iranian vessel to officially transit the strait, offering hope that more ships may soon be granted safe passage. Is the Strait of Hormuz beginning to open or does it risk turning into a new flashpoint? What does Europe's refusal to answer Trump's call for help reveal about transatlantic relations?