Of course the deal is not perfect but it is a diplomatic achievement that is much better than the alternative - war. The deal does have safe guards built in (that seem to be ignored by those who oppose) that will immediately replace and increase sanctions against Iran in the event that the Iranian government violates what has been negotiated and agreed to. Also, the United States was not alone in working on this deal. If the United States Congress rejects this agreement it will further weaken our standing amongst world leaders as the champion for diplomacy.