By Phil Stewart WASHINGTON, April 12 (Reuters) - A U.S. naval blockade of Iran is a major, open-ended military endeavor that could trigger fresh retaliation from Tehran and put tremendous strain on an already fragile ceasefire,

In 2011, President Barack Obama declared it was time for America to leave behind the wars in Iraq and Afghanistan and “pivot” to Asia to counter the rise of China. Fifteen years later, the U.S.

Iran said it had no plans for more nuclear talks with the U.S. after negotiations brokered by Pakistan broke down, but a foreign ministry spokesman said diplomacy would continue. “No program has yet been announced for the time,