Michael Hampton:

Citing the Central Intelligence Agency's "blowback" principle, Paul explained that U.S. intervention in Middle Eastern affairs over the past several decades contributed to anti-American sentiment and helped create enemies, some of whom are today's terrorists. This didn't go over too well with Rudy Giuliani, who seems to know little about U.S. foreign policy for someone who supposedly led his city through the worst international terrorist attack in U.S. history.

Andrew Sullivan:

Giuliani, interestingly, openly lied about Ron Paul's position on 9/11. Paul specifically did not make a statement, as Giuliani immediately claimed, that the U.S. invited 9/11. I rewound to double-check. It was the Fox questioner who ratcheted up the stakes on that question, not Paul. Paul demurred on a specific answer and switched the question to the general issue of blowback. As to who's right, the answer is both.

Gene Healy:

Remember, the war on terror, Giuliani says, is something he understands "better than anyone else running for president." The sad fact is, that might even be true, considering everyone else up on that stage except for Paul. But it's sort of like winning "Best Complexion" at the Leper Colony.

Jesse Walker:

The way I see it, there's three possibilities here:

1. Giuliani lives in a bubble so thick it makes the president look well-informed. He really has never heard the blowback theory before, even though it is common currency in policy circles.
2. Giuliani is familiar with the blowback theory, but is distorting Paul's views by suggesting America's air raids on Iraq were supposed to be the only intervention precipitating 9/11. (Along similar lines, you'll note that he effectively attributes to Paul the phrase "invited the attack" even though it was the moderator, not the congressman, who used that term.)
3. Giuliani wasn't being that crafty. He is aware that the bombings were not America's only Middle Eastern intervention of the '90s, and he knows that Paul knows this too. He is familiar with the blowback theory and was just playing dumb for the crowd. Put more succinctly, he's a dishonest demagogue.

David Weigel:

Prediction: The overlap between people who thought the Democrats were wrong to purge Joe Lieberman and people who think the GOP would be right to purge Ron Paul will be around 100 percent.

Radley Balko:

As for Saudi Arabia, seems odd that a man who got paid to help improve the image of the country that produced 16 of the 19 September 11 hijackers, and that continues to fund, foster, and protect hateful anti-west, anti-liberal propaganda within its borders, would have the gall to lecture Ron Paul about his war on terror bona fides. Someone needs to ask Giuliani about his representation of the Saudi government in the next debate.