July 28, 2008: The war on terror has cost nearly $900 billion so far. World War II cost, at the time (in current dollars) over four trillion dollars. At the time, the costs amounted to over a third of U.S. GDP. The war on terror is costing about one percent of GDP. So while war may appear to be getting more expensive, relative to the amount of money available, it's actually getting cheaper.

The initial cost of World War II, and most wars that came after it, will eventually double because of the cost of taking care of the veterans. There were over a million casualties in World War II, many of them serious, with long range effects. The long range health problems were not anticipated, nor were the more expensive treatments.

As a percentage of GNP, military spending continues a decline that has been going on since the 1960s (when, because of the $686 billion cost of the Vietnam war, defense spending was 10.7 percent of GNP). That went down to 5.9 percent of GNP in the 1970s and, despite a much heralded defense buildup in the 1980s, still declined in the 1980s (to 5.8 percent.) With the end of the Cold War, spending dropped sharply again in the 1990s, to 4.1 percent. For the first decade of the 21st century, defense spending is expected to average 3.4 percent of GNP. Most of the current defense budget is being spent on personnel (payroll and benefits), and buying new equipment to replace the Cold War era stuff that is wearing out and to pay for operations in Iraq and Afghanistan.

This trend is all because of the industrial revolution of the 19th century, which created a lot more money, much of which nations promptly squandered on wars they could not have afforded earlier. The American Revolution, for example, cost the United States less than $2 billion. The main reason for the low cost, compared to later wars, was that there simply was not a lot of wealth (money or goods) to scrounge up for the war.

The United States has always been enthusiastic of spending enormous amounts on weapons, ammunition, supplies and equipment for the troops, with the idea of keeping U.S. casualties down while still winning the war. Thus during World War II, U.S. combat deaths were 300,000 (plus 100,000 non-combat). The Soviet Union, on the other end of this scale, lost 10.7 million dead in combat (including 4.4 million captured and missing), and nearly 20 million civilians killed as well. Of all the major combatants in World War II, the U.S. had the lowest casualty rate (about 2 percent). Russia lost about 15 percent of its entire population during the war.

The U.S. kept its losses down partly because of the amount of money spent per person in the military (over $250,000). The current casualty rate is a third of what it was during World War II, and the amount spent per person has more than tripled (exact comparison is tricky, as all military expenses were counted during World War II, while the current war is being fought with only a small portion of American military might, and the navy and air force continue to take care of many non-war-on-terror responsibilities.)

All dollar figures mentioned above are in terms of 2008 (inflation adjusted) dollars.