David Sanger: “President Trump likes his military and diplomatic victories quick, clean and decisive.”“On his desk in the Oval Office, he keeps models of the B-2 bombers that took out three Iranian nuclear sites in one night, not quite a year ago. In the opening weeks of the Iran conflict this year, he talked often about replicating his success in Venezuela — ‘the perfect scenario,’ he said — shorthand for overthrowing a troublesome leader with one quick commando raid, and replacing him with a pliant, American-friendly successor.”“But now, Mr. Trump has hit the stalemate phase of his presidency.”