The current population of U.S. is about 314 million or about 5% of the world’s total population. The 15.0$ Trillion U.S. economy is the largest in the world and accounts for nearly one-fourth of the world’s total GDP.

Though the U.S. is separated from the rest of the world by oceans on two sides, an peaceful ally in the North and a failed state in the South, the country spends the most on military than any other country in the world including the other military superpower Russia. In 2010, the U.S. defense expenditures totaled $698 billion representing an 81% increase over the previous decade. Despite rising social and economic problems domestically, as the world’s policeman the U.S. is forced to allocate a large chunk of precious resources for the military.

Though having only 5% of the world’s population, the U.S. spent about 42% of the global military spending as shown in the following chart:

Click to enlarge

Source: CFR

From the 1999 article “A Manifesto for the Fast World” in the New York Times by Thomas L. Friedman:

“The hidden hand of the market will never work without a hidden fist. McDonald’s cannot flourish without McDonnell Douglas, the designer of the F-15. And the hidden fist that keeps the world safe for Silicon Valley’s technologies to flourish is called the US Army, Air Force, Navy and Marine Corps.”