New twist on the WMD in Iraq

This is the one thing that gets me when people bitch that the US went to war “for the wrong reasons”. My question is, do we blame a cop for shooting someone waving a gun and threatening people, when that gun turns out to be plastic? Of course, hindsight is always 20/20.

Why would this be any different? Saddam wanted people to think he had WMD - are we supposed to know better than his own people?