A classic quandary facing any Congress is deciding just how deeply to get involved in the making of foreign policy. It’s an area where the president usually is given wide berth, and lawmakers traditionally are wary of getting too invested on the front end of tough international decisions, because that means they own the messy consequences of a bad decision on the back end. Yet at the moment, the Republicans running Congress are planting their flag firmly on the side of demanding not just a say in, but a right to veto, any coming nuclear deal with Iran. This raises a basic question: Could Congress blow up international negotiations led by […]