This is another time. If you judge the war a failure on the basis of long-term consequences, then consider this: if Germany had won WWII, we'd have seen the fall of the Soviet Union, a non-communist China, Germany dominating a Europe under a united government...sort of like now, right? But believe me, Germany did not win WWII unless you change the criteria of "win" and open your period of consideration up beyond the time of hostilities.
What we did accomplish in Iraq was to prove that militant Islam can be beaten in the field, that an army from a "soft" Western government can apply a 25:1 kill ratio to the jihadis, and that there is nothing inevitable about the victory of Islam. Was this worth 4500 lives? I'd offer Chou En Lai's answer when asked about the French Revolution: "It's too early to tell."
Strategically, though, there is a considerable change for which the Iraqi wars may have bought us time. The threat of a Saddam Hussein (or Iran, or whoever) taking over the oil fields of Saudi Arabia is no longer an existential threat against the world economy. When Saddam took Kuwait and turned his eyes south, it was. That's why we had the troops there. And why we're unlikely to have to do that again. And why the Saudis are suddenly interested in nuclear weapons, because the days of "blue-eyed slaves" are over.
“Was this worth 4500 lives?”
On the other hand, 4500 lives doing what, and compared to what? Every individual death is a tragedy, including the thousands dead from the Pentagon and WTC attacks, the embassy bombings with hundreds dead and thousands maimed, the USS Cole, the deaths of those manning the borders, and those who die from living in towns where teenagers drive.
Re-electing Dinkins for another term as NYC mayor would have cost more lives. At its worst, the mortality rate of soldiers in Iraq was like being 38 in NJ. In absolute terms, the number is small. The question is, what was the trade off?
I think, at least until we abandoned the gains, it was worth it. Probably the strongest argument here that it wasn’t worth it was that we should have known we’d elect “progressives”, and thus shouldn’t have bothered...but if that’s the case, we’re done. Reagan was just wasting his breath, because he should have known there’d be a Clinton, an Obama, and he should be condemned for fighting the fight. I’m not there yet.