The messy relationship between Benjamin Netanyahu and Barack Obama began, appropriately enough, in a janitor’s office at Reagan National Airport in March 2007. U.S. and Israeli diplomats have been cleaning up ever since, as the two men have left a path littered with personal slights and policy differences. But their confrontation over Netanyahu’s politically tinged speech to Congress Tuesday could end up being their messiest yet, affecting the outcome of U.S.-Iran nuclear talks, the upcoming election in Israel and the future of the Middle East. Bibi and Barack’s hastily arranged first meeting was, in fact, cordial and respectful, according to those who were there.