I wrote this in 2007:

One of the most important reasons to wage war is that people expect to win.
Well, history tells us that losing a war is statistically at least as likely as to win it, but statistics cannot reveal the true horror.

Even many victories are questionable.

So, how shall we decide whether a conflict was won or lost?
The most basic condition that needs to be fulfilled is that a won war actually improved the situation for the country that "won" it in comparison to a "defeat" or no war at all.

Well, this is remarkably difficult to fulfill. Philosophy still doesn't provide us the tools to weight variables like killed citizens, wounded citizens, money, resources other than money, influence, fame and prestige. As every war that's claimed to be "won" included both losses and gains, it's probably impossible to claim victory at all based on math. But perceptions alone as measure for victory or defeat don't help either as everyone is thoroughly manipulated in his perceptions at the end of a war.

Anyway, it cannot hold up to serious thinking that some people claim that victory or not is simply decided by mission accomplishment. To accomplish a mission doesn't tell much, as missions almost never include comprehensive cost limits.

It's certainly no victory to accomplish a small mission that benefits the own country only marginally at costs of several thousand own KIA and several ten thousand own WIA as well as some hundred billion dollars expenditure.
That's also my rationale for why it was a blunder; marginal advantages gained at very high costs.