As for why we're not making arrests: the trail has had 7 years to go cold.
A thought occurs to me on why Clinton didn't harp on Iraq: it wouldn't give him any political advantage to do so, because he wasn't running against Saddam Hussein. It was much better for his re-election campaign to link McVeigh to Rush Limbaugh, Bob Dole, and Newt Gingrich than to link him to Saddam Hussein.
No, but if in or shortly after 1992 Clinton had thought he might again face Bush I in 4 years, having specific knowledge of Bush-Hussein dealings prior to or during the Gulf War similar to those that Bush had previously maintained as CIA Director with Panamanian dictator Manuel Noriega could have been at least as potentially useful to the Clintons as those 400+ FBI files Clinton had on other political adversaries- and allies.
-archy-/-
The Clinton Administration, made a concious effort in 1993, with the WTC bombing, to shift US Government Policy regarding ALL TERRORISM as State Sposored, to the work of Individuals. This way they could treat it as a Law enforcement probblem, and not ever be burdened by the Politically Risky pursuit of State Actors.
BTW, that was the most IMPORTANT PART of Bush's Axis of Evil speech. In one quick turn he put the emphasis back where it belonged, and without any of the Talking heads noticing. (mostly because they refused to call the Previous Administration on it).....