Within the partisan drivel, a morsel!!
I'm suddenly fascinated. Are you suggesting that our involvement in WWII began with the invasion of a foreign nation other than Japan or Germany? I'm really interested to hear the answer to that.
The history I know is that our involvement in WWII began defensively, after we were attacked at Pearl Harbor. In that way, our introduction to WWII is analogous to our involvement in Afghanistan (which I have repeatedly said is a justifiable engagement, IMO) because each was started only after an attack by another force. Iraq, you'll note, had not attacked us, thus making our participation in a war in that country the result of our own hostilities toward that sovereign nation.
Again, from both a political and a military standpoint, WWII is not an apt precedent for justifying what we've done in Iraq or what we should or should not do elsewhere as a preemptive measure.