The Globe and Mail reports in its Thursday edition that the United States targeted Iran's coastal defences and missile sites Wednesday after reinstating a naval blockade, while Iran threatened to halt more regional energy exports, saying it was in an "existential war with America." A Reuters dispatch to The Globe says the recent escalation follows the collapse of a truce, increasing fears of a return to full-scale war, though analysts consider that less likely. Hostilities increased after Iran announced it closed the Strait of Hormuz. Brent crude oil reached a one-month high of $84.95 (U.S.) a barrel yesterday. U.S. Central Command said military strikes on Iran's Greater Tunb Island targeted coastal defence systems and cruise missile sites, starting at 6 a.m. ET and concluding within 90 minutes. Nine hours later, Central Command reported a second wave of strikes. U.S. officials told Reuters that strikes aimed at reopening the strait are also targeting Iranian military capabilities to eliminate before complex operations. The U.S. military also said it disabled an unladen oil tanker attempting to sail toward Iran's Kharg Island after it ignored multiple warnings, firing Hellfire missiles into the ship's smokestack.