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Republican Senator Lindsey Graham has repeatedly called for a stronger stance against Syrian President Bashar al-Assad.
Graham listened to President Barack Obama's address to the nation Tuesday night, and said Obama made a compelling, impassioned moral case for U.S. intervention in Syria.
"It's impossible for him not to react if diplomacy fails – not to act," said Graham. "He's painted himself into a corner. The leader of the free world can't say all these things, and at the end of the day do nothing."
Just a few weeks ago, Graham stood in the White House driveway and criticized the president, calling on him to talk about Syria in broader terms.
"I'll continue to trash him in that regard," said Graham.
Graham at the time was trying to extract leverage from the escalating situation, and get Obama to do more in Syria, to arm the rebels.
"The president is in a bind. People don't want to get involved in the Middle East any more than they have to," said Graham.
But, Graham said, the country is losing the lessons of 9/11.
Graham went on to say that there is a lot to be learned from Iraq, but it cannot overshadow the lessons of 9/11, which he said "are pretty simple to me. Safe havens for al Qaeda are forming in Syria, they're beginning to form again in western Iraq."
For more of reaction to Obama's speech from Senator Lindsey Graham, click on the video above.