HONG KONG — China has been a quiet — if crucial — player in the Iran war , as U.S. military action upends the global economy . That changed Tuesday, as Beijing assailed the American blockade of Iranian ports as “dangerous and irresponsible,” while leader Xi Jinping warned against a return to the “law of the jungle.” This public intervention was its most significant to date as China, which has close ties with Iran , faces growing pressure to use its influence to bring an end to the war. Some of