Trump seems trapped by Iran war, even as he wields world’s biggest hammer

He has discovered limits on his power that he could have scarcely imagined as he began full combat operations on Feb. 28, when he set out goals for a swift end to Iran’s nuclear program and the overthrow of the country’s government. Five months later, those goals remain almost entirely unaccomplished. And Trump, once confident that overwhelming force would enable him to pursue in Iran what he proudly called the “Venezuela model” — a change of government to one amenable to U.S. control — is now hesitant to plunge back into major combat operations that his intelligence agencies assess are…