$30 Billion Boondoggle: Meet 5 Super Weapons That Failed Washington is more than willing to spend on wonder weapons, but that doesn't mean it is always worth it. Here's What You Need to Know: A lot of money went down the drain thanks to these weapons. The United States spent $610 billion in 2018 on defense, roughly one-third of all military spending on the planet—but that doesn’t mean that money is always being used efficiently. Over thirty years, the U.S. Army has engaged in two long-term wars and several briefer ones without replacing the major weapon systems which entered service in the 1970s and 80s.