http://en.wikipedia.org/wiki/List_of...y_expenditures
so according to wikipedia (which cites various sources)... the military expenditures are like this (2007/2008):
the US spent 583 billion dollars
the EU spent 311 billion dollars
China: 59.0
Japan: 41.7
Russia: 41.1
India: 26.5
...
btw. talking about large scale war is totally unrealistic. not even if EU and US are enemies. you've all seen the cold war. having nukes ruins the fun of war.