War as a political solution

Sometimes, the only political solution is war. France and England were caught in this trap in 1938. The political solution to ending slavery in the United States was a major trigger in the civil war. I am not trying to say that this is the case in Iraq. I am only pointing out that non-violent political (and diplomatic) solutions have limitations. To use a crude example:
Someone pulls a knife on you. You have two choices:
1) Give him what he wants.
2) Shove that knife right up his ass.
A good friend replied to me that people behave differently in-groups. Quite true. However, man is still violent when working as a group. In fact, working in a group enhances his violence toward others. Hitler pulled a knife on a lot of people. The United States helped with the eventual placement of the knife. At the same time, we allied ourselves with a government that was only slightly less undesirable than the one we were fighting. The point here is that human nature does not change because we are placed into a group.
Hitler was considered to be far right. The Krupps and other private individuals and groups owned the means of production. Stalin was far left. The government owned the factories. Yet they were the same type of tyranny. If you fear Hitler more than Stalin, you would tend to vote more left. If your fear is from the left, you would lean right. The extremes are the BIG problem seeing that they are basically the same thing. However, extreme situations call for extreme measures. Survival may depend upon taking extreme measures. The balance between the two can be a tough one.