The threat we are faced with is not more serious. It's more immediate, but that's a different matter. We are not at this point facing the possible imminent destruction of the human race. We were then.
"Taking the fight to the aggressor" - that really is rich in the context of the invasion of Iraq, for all that Saddam was a very nasty piece of work, who had done his share of aggressing in the past, largely as a proxy for the USA, in the case of the war with Iran.
The international terrorists who carried out September 11th and the other similar atrocities, had nothing to do with Iraq. They have now, of course, and potentially they are far strtonger and more dangerous than they were before. "Things aren't going entirely their own way"? They are going far far better than they could ever have dreamed was conceivable.