While they were at odd somewhat ideologically, they both did share a common enemy. The United States. Also, proof of the tie that formed after 9/11 can be found in this article about Al Zarqawi.
Link.
Excerpt: Abu Musab Al Zarqawi has been presented both by the Bush administration and the Western media as the mastermind behind the "insurgency" in Iraq, allegedly responsible for the massacres of Iraqi civilians.
Zarqawi is the outside enemy of America. The Bush administration in official statements, including presidential speeches, national security documents, etc. has repeatedly pointed to the need to "go after" Abu Musab Al Zarqawi and Osama bin Laden.
"You know, I hate to predict violence, but I just understand the nature of the killers. This guy, Zarqawi, an al Qaeda associate -- who was in Baghdad, by the way, prior to the removal of Saddam Hussein -- is still at large in Iraq. And as you might remember, part of his operational plan was to sow violence and discord amongst the various groups in Iraq by cold- blooded killing. And we need to help find Zarqawi so that the people of Iraq can have a more bright -- bright future." (George W. Bush, Press Conference, 1 June 2004)
The official mandate of US and British occupation forces is to fight and win the "war on terrorism" on behalf of the Iraqi people. Zarqawi constitutes Washington's justification for the continued military occupation of Iraq, not to mention the brutal siege of densely populated urban areas directed against "Al Qaeda in Iraq" which is said to be led by Zarqawi."
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On a side note, Zarqawi was killed in Iraq by 2 500lbs bombs dropped by American aircraft.
On this PBS web page in an article about the terrorist training camp at Salman Pak that trained domestic and foreign fighters for the purpose of attacking American interests. Link.
Excerpt:
"To you, then, the likely suspect here is the government of Iraq and Saddam in all this terrorism. And yet we're looking the wrong way?
I assure you, and I'm going to keep assuring you, that all these things are obvious. I don't know why you don't see it. When we were in Iraq, Saddam said all the time, even during the Gulf War, "We will take our revenge at the proper time." He kept telling the people, "Get ready for our revenge."
We saw people getting trained to hijack airplanes, to put explosives. How could anybody not think this is not done by Saddam? Even the grouping, those groups were divided into five to six people in the group. How about the training on planes? Some of these groups were taken and trained to drive airplanes at the School of Aviation, northern of Baghdad ... .Everything coincides with what's happening.
In addition to that, we heard in the news about meeting some of those hijackers with the Iraqi intelligence people in Prague, and even getting money to get trained on flying airplanes in the United States from the Iraqi intelligence.
[Did you hear that some of those training at the camp were working for] Osama bin Laden?
Nobody came and told us, "This is Al Qaeda people," but I know there were some Saudis, there were some Afghanis. There were some other people from other countries getting trained. They didn't tell us they were part of Al Qaeda; there's no such thing. ... In this camp, we know that those are Saudis, or Arabs are getting trained. Nobody will talk about Al Qaeda or any other organization.
They're just people.
Yes.
Who clearly wanted to ... or were interested in doing terror, becoming terrorists?
This camp is specialized in exporting terrorism to the whole world. ..."
As well as this site that talks about how Salman Pak was home to special weapons facilities. Link.
And one article about how Al-Zawahiri, the second in command of Al Queda, says in a video that Iraq is the central front in the war on terror. Link.
Its the popular thing to do. And you're trying to take credit for that...? 
