The United States in comparison, has significantly less - 1.4 million - but, as Statista's Martin Armstrong notes, when assessing the overall power of the world's military forces, the U.S. comes out on top, ahead of Russia and China in second and third, respectively.

The index "utilizes over 50 individual factors to determine a given nation's PowerIndex score with categories ranging from military might and financials to logistical capability and geography."

While a rating of 0.000 would represent the perfect score, it is considered realistically unattainable.