Different times, with different needs. I don't quite buy that Saddam had more to fear from terrorists-- any more than he had to fear from his own insiders. But it is known that he was providing refuge and gainful employment for known terrorists, Abu Nidal for one.
He gave them all the Muslim lip service that they likely craved, and provided grouds and protection for training.
But at a more basic level, Saddam was a madman in charge of too much territory and too much technical and military ability. He was going to be nothing but a continuing danger to his neighbors and to the U.S. and it was in everybody's best interest to dispose of him. The actual legal reason for the invasion was merely his refusal to abide by U.N. resolutions. That's plenty good enough. The rest is just icing.
But I would caution to stay tuned on the WMD issue. It isn't over yet. Some things may yet come to light.