Regarding global military spending, I recommend you take a look at the CIA World Fact Book page on the subject.
The U.S is number one, of course, and the number posted (370$ billion) is from 2003. Number two is China at $67.5 billion (2004). Next in order come Japan, France, England, Germany, Italy, Saudi Arabia, India, and Australia, ranging from $17 to $46 billion. Russia is not included because there's no way of knowing what they really spend, but it's a safe assumption that the vast majority of what's left of its Cold War arsenal is either burning in Chechnya or caked in rust.
Of that list, China is the only country one can reasonably argue we might have to fight a conventional, symmetrical war with in the next 10 to 20 years, and that would be a naval/air war in which we would interdict an invasion of Taiwan (which is extremely unlikely to occur).
I have yet to hear a compelling argument as to why America continues to pursue an arms race with itself.