President Shimon Peres said in an interview on Monday, a day after his meeting with U.S. President Barack Obama, that he believes that Obama would not allow Iran to have a nuclear weapon because that would affect the American economy.

“Imagine that Iran becomes the ruler of the Middle East, and Saudi Arabia and the principalities will be under their rule,” said Peres. “It would be a catastrophe.”

He added that such a situation would also make for a security risk that would allow terrorists to enter the U.S. and kill millions.

“It’s very serious business, it’s not just a theory,” said Peres. “The problem is around strategies, tactics and timing which is normal, but basically I believe the President has decided. He made it clear. He said all options are on the table, including the military option.”