The terrorist goings-on in Oklahoma began, and are the result of, the resettling of Iraqi Republican Guards in and around OKC after the first Gulf War. That act gave terrorists a foothold here and a base of operations. Since nothing has been done to clean up the area and get rid of them, they are still there and they continue to operate from there. And all of the "coincidences" involving OKC and Norman, and the terrorist traffic that has moved through there (such as Atta and other 9/11 operatives), highlights the fact that there has definitely been a link between Iraq and Al Qaeda over the past decade.
Re Al Qaeda / Iraq link
You probably knew this, but the 1998 US indictment of bin Laden indicates an al Qaeda / Iraq link...
4. Al Qaeda also forged alliances with the National Islamic Front in
the Sudan and with the government of Iran and its associated terrorist
group Hezballah for the purpose of working together against their
perceived common enemies in the West, particularly the United States.
In addition, al Qaeda reached an understanding with the government of
Iraq that al Qaeda would not work against that government and that on
particular projects, specifically including weapons development, al
Qaeda would work cooperatively with the Government of Iraq.