"But the United States has to negotiate with other countries. We have to negotiate with Iran. And the alternative of not reaching an agreement, you know what it is? It's war. Do we really want another war, a war with Iran? An asymmetrical warfare that will take place all over this world, threaten American troops?"
Sanders announced his support for the Iran deal on Friday after a phone conversation with President Obama.
The day before, Sen. Charles Schumer (D-N.Y.) announced his opposition to the deal, rattling the Senate Democratic Caucus. Schumer, the most senior Jewish member of Congress, is expected to lead Senate Democrats beginning in 2017.
Sanders argued that the deal deserves a try. "I think we go as far as we possibly can in trying to give peace a chance, if you like," he said. "Trying to see if this agreement will work. And I will support it."