Here's my opinion on the matter:
Short answer - Yes.
Long answer - Partially yes, but not in the way some would like to portray it. One of Al Qaeda's favorite citations against the United States the state of the Palestinians and the intifada, which this time around was nothing but a terrorism campaign. Saddam was instigator. He did his part to ensure the intifada continued. With Saddam out of the way the instigation has been greatly reduced. It's a lot harder for Zawahiri and Bin Laden to whip up followers when the Palestinians themselves aren't taking the same roads they did before. Personally I have my doubts as to how much the Al Qaeda leadership and the rest of the Arab and Moslem world really cares about the Palestinians. The Jordanians fought a brutal war against them, and the Palestinian migration into Lebanon following this war was the cause of that country's long civil war. Reminds me of so many white liberals who say they care about minorities and the poor, but would never want to live around them if they didn't have to. Pro-Israel does not inherently mean Anti-America.