When the Cold War ended, so did the era of huge conscript armies, masses of tanks (the Soviet Union had over 50,000 when the end came) and comparatively large numbers of combat aircraft and warships. Suddenly everything got smaller, and more expensive. Conscripts were replaced by a lot fewer professionals, who got paid a lot more money. This was something the British pioneered in the 1960s, followed by the United States in the 1970s. When the Cold War everyone ended, and everyone saw what pros could do in the 1991 Gulf War, everyone began to dismantle their conscript armies. Smaller armed forces, staffed by professionals and equipped with less, but more capable, gear, were the new norm. Thus defense spending changed as well. Much more of it went for payroll, and for buying far fewer, but higher quality, weapons. More money went into equipment, high tech stuff like satellite based communications and computers. Billions of dollars a year is spent on satellite communications alone.
With the Soviet Union gone, no one else out there wants to try and match the United States spending levels. The war on terror also has American spending going up again. Currently, the United States spends about $440 billion a year, all of Europe, about $200 billion, all of Asia, about $180 billion, the Middle East, about $80 billion. Africa and the rest of the Americas add another $20 billion or so. While nearly half the spending is by the United States. most of that money is not buying weapons, but payroll, benefits and materials needed for training and operations (food, fuel, spare parts, services.)
Not many new tanks, warplanes or combat ships are being built, as everyone continues to live off the Cold War surplus. Many countries want to build new stuff, but everything has gotten so much more expensive. Thats because computers and powerful sensors and all manner of nifty technology provide most of the lethality in new weapons. Build the old style weapons, and youre just providing expensive targets for those with the most modern weapons. Even your basic $500 assault rifle becomes far more lethal when you add several thousand dollars worth computerized accessories.
Countries are spending more on defense, but they arent buying the same kind of stuff they were two decades ago.
The Cold War arms race is back. Sort of. The Cold War arms race reached a peak in the late 1980s, when spending (adjusted for inflation), went past $1.6 trillion a year. The Soviet Union, which started the arms race in the early 1960s, couldnt keep it up, and disintegrated in 1991. After that, military spending declined by about half over the rest of the decade. The decline came to a halt in the late 1990s, and global spending began to rise again. Now annual global military spending is approaching a trillion dollars again. But its not the same. In fact, its very different. Back during the Cold War, there were over a hundred million people under arms, and each year, factories turned out thousands of tanks, hundreds of warplanes and dozens of warships. No more, not even close, even though current spending is about 60 percent of the Cold War peak. There are fewer than 40 million people under arms, and tank production rarely exceeds a few hundred a year, with annual warplane production of less than a hundred a year, and only a handful of warships.