Iran and the U.S. harden their positions as Tehran keeps its grip on the Strait of Hormuz

DUBAI, United Arab Emirates — Iran and the United States hardened their positions as a diplomatic push for a ceasefire in the Middle East war appeared to falter on Thursday. Tehran moved to formalize its control over the crucial Strait of Hormuz while Washington prepared for the arrival of U.S. troops in the region that could be used on the ground in the Islamic Republic.