Is there any justification for the Iraq War?

First, the US claimed they must invade Iraq to destroy their weapons of destruction.

Second, they invaded Iraq to make up for 9/11. But was it worth it when they lost more soldiers during the Iraq War than on 9/11.

Third, they brought up the Human Rights Injustices. But under the US occupation Iraqis have been killed had a alarming high rate. Due to the violence Bush is even compared to Saddam.

Most of America's objectives have failed miserably.

And now news has surfaced that Saddam was willing to surrender for $1 Billion.

The US has spend almost $500 Billion on the Iraq War. The UK also has spent over $7 Billion on the war. If all the rational for the war was wrong, why does the US continue to funnel billions of dollars towards a failed mission while their economy and currency are in free fall?