President Obama says the deal with Iran has made the world safer by stopping the spread of nuclear weapons in the volatile Middle East.
Secretary of State John Kerry has staked his 30-year public career on the success the negotiations. Presuming that the UN goes along, Congress now has 60 days to approve or reject the accord — as well as the lifting of US sanctions.
Republicans, including House Speaker John Boehner, agree with Israeli Prime Minister Benjamin Netanyahu that the deal is "a historic mistake." Some Democrats are skeptical, too. They worry that Iran can't be trusted, but the President invoked a phrase made famous by Ronald Reagan, "This deal is not built on trust. It's built on verification." We look at the details and the prospects of a struggle with global significance between the White House and Congress.