Hawkish Americans tend to see the Europeans as too soft and tentative - not willing to use military might. I wonder how much this has to do with our memory of war.
Mainland Europe had two world wars fought on the ground in their countries in the last century, while for America those wars were profitable both politically and economically. America became a superpower because of those wars - building industry while other countries were destroyed. Many Americans died, but the war wasn't in our country. The last time we experienced war up close was 1865 - and maybe the horror of that experience has been replaced by the myth that the second world war brought peace. The peace in Europe after WWII had more to do with the different approach to peace found in the Marshall Plan versus the Treaty of Versailles, than with the fact that Axis powers were defeated by force.
Violence brings more violence. Only love can bring peace. Is there a "right to defend" oneself or a society against aggression? Yes, but we should never think that defending ourselves successfully is a lasting solution. We might also need to learn that there are many types of violence, and we in perpetrating one form may sow seeds for another form.