Brock #6:

One of the reasons it’s so tempting for smaller first world nations to just let Uncle Sam take care of global defense is because modern war toys are very expensive. Back when B-17s and T-34 85s were state of the art, a small nation could afford to purchase or produce, and maintain a large enough number of these relatively conventional devices to deter local thugs and contribute significantly to major wars. Since the end of WWII, it has been increasingly difficult for 2nd tier powers to stay competitive with the big boys in quality of equipment. Stealth fighters, nuclear powered war ships, tanks using jet engines and exotic metal or ceramic armor, armed robots controlled from the other side of the planet. The price tag for any of this stuff adds up fast.

My point is that it would take a lot more than 2-3% of GDP for most 2nd tier powers to really provide for their own defense without relying on a much larger more powerful allied nation for backup. With the exception of Israel, Britain, France to a substantially lesser degree, and perhaps Japan, no other counties have even tried. Truth be told, a lot of the cost to even those countries has been underwritten by Uncle Sam, since we’ve paid for much of the R & D, and then sold or given U.S. technology to our allies.