I hate war just as much as the next person, but I think the main reason a lot of European countries don't want to get involved is because they have seen war up close via WW1 & 2, and they know first hand just what really happens when the battle is going on right in their front yard. Given the events of history, Germany in particular will never take part in any war because they have suffered every time they get involved. There never has been, and never will be a ground level invasion of the US, so as Americans we never worry about war, its only something that we see on the TV, not something we can look out our windows and see a bomber strafing the front lines.