We chose this war. It wasn't forced on us.
We chose this war. It wasn't forced on us. That's the crucial factor you're leaving out of your moral calculation.
The rationalization of self-defense has been exposed as false. That renders your attempted analogy with a nuclear weapon in New York completely meaningless.
The fallback rationalization was that we would close Saddam's prisons and liberate the Iraqi people from torture and abuse.
That one's been proven false now too.
If the price of winning the war we started is to abandon our principles and values, and descend into the pit of barbarism of our enemies, then that price is too high.