According to the 2000 census, there were 26.4 veterans, a million less than in 1990, but still nine percent of the population. There were 16 million veterans of World War II, and the youngest of these are in their late 70s. World War II vets are dying at the rate of nearly 2,000 a day and in another decade or so, most of them will be gone. Even with no major wars, or further cuts in the armed forces, we still have at least 15 million veterans in 20 years. The World War II veterans were always the largest group. That was a large enough fraction of the population (over ten percent, when World War I vets were included) that it had a major impact on how the nation regarded the military. But the major factor, at least until the 1960s, was that the draft took people from all levels of society. Even the ivy league colleges had ROTC and supplied graduates who served as officers for a few years. But the post World War II baby boom provided nearly two million young men each year for the draft, when the military only needed less than a quarter of that. Even without the Vietnam war, there would have been growing strife over "who shall serve." Local draft boards had to deal with the details of exactly who would go and who wouldn't. Exemptions for college, graduate school and married men were given out more freely. But it was becoming something of a lottery and even local draft boards caused friction when a lot of locals disagreed with their decisions. So the all-volunteer force would have arrived by the 1970s anyway. And with that, fewer of the young men who would become the leaders of tomorrow would serve. While the number of veterans matter, having people in high office who have served matters as well. Veterans are more than just another special interest group. They have been there when it comes to military service, and that is more important than most people realize when it comes to deciding when, and how, to use the armed forces.
