Way back in November 1998, when Republicans were hell bent on impeaching President Bill Clinton, and were attacking him for launching air strikes in Afghanistan and Sudan in August of '98 accusing him of a Wag the Dog strategy, one erstwhile Senator was busy questioning whether Osama bin Laden posed that great of a threat.
According to a Mother Jones interview published in November 1998, McCain was asked directly about the threat posed by Osama bin Laden.
You not only have had combat experience in Vietnam, but you were also a prisoner of war. When you look at terrorism right now, with people like Osama bin Laden, do you have any reservations about watching strikes like that?
You could say, Look, is this guy, Laden, really the bad guy that's depicted? Most of us have never heard of him before. And where there is a parallel with Vietnam is: What's plan B? What do we do next? We sent our troops into Vietnam to protect the bases. Lyndon Johnson said, Only to protect the bases. Next thing you know.... Well, we've declared to the terrorists that we're going to strike them wherever they live. That's fine. But what's next? That's where there might be some comparison.
So, in 1998, McCain didn't think that bin Laden was "really the bad guy that's depicted?" because "Most of us have never heard of him before". Not only that but McCain in the rest of his answer seems to be laying out a rationale against the 2003 Iraq war.
UPDATE: McCain's dismissal of the threat bin Laden posed is not to be taken lightly. In 1997 CNN had done an interview with bin Laden where he affirmed his jihad on America and most security experts at the time acknowledged that bin Laden posed a very real threat to America. In fact Al-Qaeda had been blamed for the August 1998 bombings of the embassies in Kenya and Tanzania. So for McCain to dismiss bin Laden as a serious threat in 1998 shows a real lack of grasp of the danger posed by terrorist groups like Al-Qaeda.