israel. the president is right. this is the you havest non proliferation agreement i've ever seen negotiated. >> wow. professor, why do you think this is such a polarizing issue for americans as it's turned out. not simply just for congress but for the broader american public as well. >> first of all i think that when you look at polarization in the united states, it is not just a matter of the congress. opinion in the whole count i have polarized. and there is probably 40 to 45% of the country who will be against anything president obama proposes. so that is clearly part of this. what really struck me today about the president's speech is this may have been the toughest speech i've ever seen him give in the way that he talked about his opponents other than an election campaign speech. essentially he said, if you like the people who you brought you the iraq war, you will love the people opposing the iran treaty.