The Vietnam-era draft cut a tornadolike swath through a generation of American men.
"It was a crucible question, regardless of where you came down on the war in Vietnam," Alexander Bloom, a historian at Wheaton College in Massachusetts, says of the draft. "It was a question people who did not want to go to that war had to face - whether to go to Canada, to the resistance, to teach in an inner-city high school, whatever helped you stay out. It was not something you did casually."
Those years have surfaced again with allegations about President Bush's service in the National Guard and heroic tales of war from opponent John Kerry's combat in Vietnam.
When Bush and Kerry faced the draft, eligibility was determined by complex regulations governing deferments.
"Students got out, certain occupations got out, if you had braces on your teeth you got out," says David Segal, director of the Center for Research on Military Organizations at the University of Maryland, College Park.
"Anything that the military didn't have to deal with, it didn't want to deal with because it had all these other people it could call up," he says, referring to the baby boomers reaching age 18.
That made avoiding the draft something of a high-stakes game. Stay within one or more of the safe havens until you reached age 26 and you were no longer vulnerable. But leave one of those havens and you might find yourself under fire in Vietnam.
The game favored the affluent and educated, who could go to graduate school, regardless of their genuine academic aspiration; who could find a friendly orthodontist to put on braces, no matter what the state of their teeth was.
Kerry and Bush lost their student deferments when they graduated from Yale - Kerry in 1966, Bush in 1968 - at the height of the war and the draft. In 1966, more than 382,000 were inducted through the draft. That was the biggest call-up of the Vietnam era. The second-largest was in 1968 when slightly less than 300,000 were inducted.
Kerry, from an influential family and an Ivy League school, was the type who usually found a way around the draft. So his choice to join the Navy appears unusual, particularly for someone who had just given a talk to his fellow graduates that was critical of the Vietnam War
But Douglas Brinkley, Kerry's biographer, says signing up was not surprising for the son of a one-time test pilot who spent his career in government service.
Kerry's father "felt you had a real duty to your country, almost to an obsession," Brinkley says. "John Kerry was raised with that.
"If you cut to 1965 or '66, his father was totally against the war," says Brinkley, author of Tour of Duty: John Kerry and the Vietnam War. "But there was never a sense that the Kerry boys were going to shirk their duty."
Kerry had other influences - a fascination with the story of John F. Kennedy and his PT 109 heroics in World War II, and a close group of friends at Yale that included the grandson of Gen. John J. "Blackjack" Pershing, U.S. commander in Europe in World War I.
"It was the uncool thing to do - not to join the military," says Brinkley, director of the Eisenhower Center for American Studies at the University of New Orleans and editor of American History magazine.
Because he was not drafted, Kerry could choose his service - the Navy where only pilots were seeing much combat - and he could try for officer candidate school, a cinch for a Yale graduate.
One way out of going to Vietnam was the National Guard.
"In every other war prior to Vietnam, up to and including World War II and Korea - and in every war since - the military has used the National Guard as the primary mobilization base," Segal says. "But with Vietnam, the Kennedy and Johnson administrations made the decision not to draw heavily on the reserve components, instead to primarily use conscription."
Segal speculates that this was because so many baby boomers, who, unlike those in the Guard, had done no service, were available for the draft. Whatever the reason, he says, "The decision not to deploy the Guard made it a way to get out of going to war without going to Canada and, indeed, to do something honorable, to put on the uniform of your country."
John C. McWilliams, a history professor at Penn State, agrees. "The National Guard was very appealing for those individuals who did not want to go to Vietnam but instead stay home and live life as normal as possible," he says.
The problem was that once that became clear, a long line formed to get into the Guard. Segal says the decentralized nature of the National Guard makes it impossible to know how long the line was. With entrance decisions made on local levels, the Guard was open to charges that influence was used to get to the head of the line.
"Clearly, there was some political pull involved," Segal says. "It is anecdotal evidence, but there is story after story of people jumping over others on the waiting list."
The system, he says, resulted in a National Guard, that was "virtually lily white and largely middle class or better. The longer we were at war, the more connected you had to be to get into the Guard."
Most Guard units required six months of active duty, followed by weekend assignments. The Air National Guard that Bush joined required a two-year hitch for flight training. Bush has said that is the reason it had no waiting list.
Segal finds that hard to believe. "In 1968, I don't think there was a National Guard unit in the country that did not have a waiting list," he says. "But no one would know that except the people in the unit itself."
In 1994, Bush said his reason for joining the National Guard was the standard one. "I was not prepared to shoot my eardrum out with a shotgun in order to get a deferment. Nor was I willing to go to Canada. So I chose to better myself by learning how to fly airplanes," Bush told an interviewer in Houston.
In more recent interviews, Bush has promoted his time in the Guard, noting that many Guard members are in Iraq.
Segal says that is true. "All the discussion about avoiding going to the Vietnam War by going to the Guard should not tarnish the Guard today. ... The military is probably using the Guard today in many ways more than it did even in the pre-Vietnam period."
Many say that if Bush did miss some Guard meetings in the waning years of his commitment in the 1970s, he was not alone. With the Vietnam War winding down, the locally controlled Guard units were often lax about such things.
Trying to end the inequities of conscription, the government held the first draft lottery on Dec. 1, 1969. It would determine the order of call-up in 1970 for everyone born between 1944 and 1950 still eligible for the draft.
One by one, 366 dates were pulled out of a large glass jar. If your birth date was the first pulled, you got No. 1 and would be the first to be called up. If you were born on the last date called, you got No. 366 and would never have to worry about the draft again.
"It was a Monday night," remembers McWilliams, then a student at the University of Baltimore. "Everybody was watching on TV or listening on the radio. There were a lot of screams throughout that night."
You could still fail the physical or decide to enlist. The new rules closed off the perpetual student deferment, though, delaying induction only until the end of that academic year.
Segal says in some ways it did make the system fairer. "At the beginning of the war, in casualty figures, African-Americans were grossly over-represented. That evened out with the lottery system. So it was fairer on that basis."
But it drew a stark line between those who had to face this crucial decision and those who could go on with their lives as if there was no war. To see the draft's impact on that generation, ask any man today who was subject to the lottery what his number was. Most can still rattle it off with no hesitation.
When that first lottery was held, Bush was in flight training in Texas. Kerry had been home from Vietnam for a few months. He had served on a ship off shore, but, Brinkley says, in 1968 asked for the command of one of the sleek 55-foot Swift boats that were doing uneventful Coast Guard duty in Vietnam.
The mission changed a few weeks later, and the Swifts were sent up Vietnamese rivers, essentially to draw enemy fire and respond. Kerry's time in that combat earned him a Silver Star, a Bronze Star and three Purple Hearts, wounds that qualified him for an early trip home, which he took.
The lotteries continued for four more years, but the call-ups diminished. The draft was abolished in 1973, replaced by an all-volunteer Army.
But decisions made then - by institutions and individuals - still cast shadows over the country.
"It continues to go on and on and on, almost 30 years after the fall of Saigon," says historian Bloom, author of Long Time Gone: Sixties America Then and Now. "In '91, after the gulf war, we were supposed to have kicked the Vietnam syndrome, put Vietnam behind us. But that was true of Grenada, with Panama. We are haunted by Vietnam."