Tony Blair may have not learned an important lesson from the Iraq war. The former British prime minister is now suggesting that preemptive military action against another country may be necessary.

Blair told ABC's Christiane Amanpour Sunday that all military options should be on the table when it comes to keeping Iran from obtaining a nuclear weapon.

"It is a problem," Blair said. "I don't know. You don't know. You're making a calculation of risk. When you're in the hot seat of decision making you have to decide. Maybe if they got them, they would never use them. But I don't think, if I was a leader today, and certainly, this is the view I took then, I don't think I would take the risk."

"So what would you do?" Amanpour wondered.

"I would tell them they can't have it and if necessary they will be confronted with stronger sanctions and diplomacy. But if that fails, I'm not taking any option off the table," said Blair.

"So you see a military possibility against Iran?" the ABC host asked.

"I don't want to see it," Blair replied.

"But you're saying it has to happen," Amanpour pressed.

"I don't want to see it but I'm saying you cannot exclude it because the primary objective has got to be to prevent them from getting a nuclear weapon," said Blair.