Global defense spending is now over $1.5 trillion a year. That's nearly 2.8 percent of global GDP. That's up about fifty percent in the last decade. But troop strength has not increased, it has decreased in that time. What's happening is that technology is replacing troops. The top hundred arms and military equipment manufacturers now have sales approaching half a trillion dollars a year, and that has nearly doubled in the last decade.
The American experience in Iraq and Afghanistan has demonstrated to military leaders worldwide that high tech, carefully selected and intensively trained troops are superior to anything else. But even nations that cannot afford to go high tech, are forced to buy new equipment because Cold War era stuff is wearing out.
For many poor nations, the Cold War was a period where they could depend on lots of cheap, or free, military equipment from the two competing superpowers (the U.S. and the Soviet Union.) When the Soviet Union dissolved in 1991, that competition ended. While there was a lot of Cold War surplus gear available (as the major Cold War adversaries slimmed down their forces), all that gear is old and worn, no matter who owns it now. It's boom time for the merchants of death, as so many nations are forced to buy new stuff, or become disarmed.