Iran has warned that European countries supporting U.S. military operations could potentially face retaliation, raising fresh security concerns across NATO’s southeastern flank. Iran’s new military chief said assistance provided to U.S. forces could be treated as complicity in Washington’s actions, putting several European states under increased pressure as tensions with Tehran rise. Albania, Bulgaria, Croatia, Greece, Romania, Serbia, Bosnia and Herzegovina, Kosovo, Montenegro and North Macedonia could face heightened security concerns because of their strategic locations, NATO links or relations with Washington.