With age of empires and ideologies behind us, world moves forward in era where military might become useless irrelevance military

Democracy: Military hegemony not necessarily profitable in post-medieval era

The Economist

BACK when I lived in Hanoi, admirals with the American navy would periodically come through on official visits to cultivate America’s diffident but promising new defence alliance with the Socialist Republic of Vietnam. Because Vietnam also claims to be an ally of the Socialist Republic of China (you would too, if you had a border with them!), these visits were rather sensitive, and both the Americans and the Vietnamese would have to come up with formulations to explain their partnership that elided its real reason, namely to deny China naval supremacy in the South China Sea. The Vietnamese would talk a lot about being friendly with all nations, and the Americans would say they were there because of America’s powerful strategic interest in preserving the security of global sea lanes.

See more at the Economist, an excellent news source. Also, from CIA World Fact Book About US Military:

United States Armed Forces includes the US Army, US Navy (includes Marine Corps), US Air Force, US Coast Guard; note – Coast Guard administered in peacetime by the Department of Homeland Security, but in wartime reports to the Department of the Navy (2013). Military service age and obligation is 18 years of age (17 years of age with parental consent) for male and female voluntary service; no conscription; maximum enlistment age 42 (Army), 27 (Air Force), 34 (Navy), 28 (Marines); service obligation 8 years, including 2-5 years active duty (Army), 2 years active (Navy), 4 years active (Air Force, Marines); DoD is eliminating prohibitions restricting women from assignments in units smaller than brigades or near combat units (2013)

Military expenditures:

4.35% of GDP (2012)

country comparison to the world: 9

4.75% of GDP (2011)
4.35% of GDP (2010)