Paul, Giuliani exchange sharp words over 9/11

Rep. Ron Paul sparred with former New York City Mayor Rudy Giuliani again during Tuesday's debate.

(CNN) — Reminiscent of the tussle the two had in a May GOP debate, on Tuesday, former New York City Mayor Rudy Giuliani and Texas Rep. Ron Paul reignited a war of words over 9/11. Giuliani took issue with Paul's contention that in "220 years" Americas has never been under imminent attack. Paul was responding to a question on whether the president needs Congress to approve a potential invasion of Iran. "I don't know where he was on September 11," Giuliani said in response to Paul's comments. "That was 19 thugs," Paul sharply fired back. "That had nothing to do with a country." "Well, I think it was kind of organized in Afghanistan and Pakistan," Giuliani said. "And if we had known about it, maybe — maybe hitting a target there, quickly, might have helped prevent it." The debate was similar to an exchange the two had in a May 23 debate, when Giuliani sharply criticized Paul for saying the 9/11 attacks were the result of America's involvement in the Middle East. "As someone who lived through the attack of September 11 — that we invited the attack because we were attacking Iraq — I don't think I've ever heard that before, and I've heard some pretty absurd explanations for September 11th," Giuliani said then. In response, Paul stood by his comments and said that "if we think that we can do what we want around the world and not incite hatred, then we have a problem … They come and they attack us because we're over there."