In his first AJC interview since his daughter's unsuccessful bid for his old seat, former U.S. senator Sam Nunn worries about the letter that Republican senators wrote to Iranian officials, warning that nuclear negotiations with President Barack Obama would be futile, and a Washington so divided that it risks the nation's clout abroad on some serious, life-and-death issues.

“Whatever the intent of the letter, and I don’t try to divine that intent, it’s being interpreted around the world as a large part of the Republican Senate suggesting that the Ayatollah should not trust or make agreements with a U.S. president,” Nunn said. “To say the least, it’s a very significant departure from the norm of American foreign policy.”

Specifically, Nunn worries about the impact the Iranian letter might have on the disparate coalition – which includes Russia, France, China, Britain, and Germany – behind the economic sanctions that have driven Iran to the negotiating table.