WASHINGTON -- Before a roadside bomb in Baghdad burned and tore apart Jerry Majetich, before 62 operations put him back together, even before he volunteered for the Marines, then the Army, there were five older brothers who’d enlisted and a mother who’d served as an Army nurse in Korea.

His family background shaped former Staff Sgt. Majetich, who’s now 42 and a single father and investment firm vice president in Jacksonville, Fla. Despite the torment since the 2005 blast, that history is part of what moved his 21-year-old son to consider leaving college to pursue a military career, and his 17-year-old daughter to join her high school Reserve Officers’ Training Corps.

“I’d be thrilled if they chose to serve,” he said. “Despite everything, I believe in military service.”

January marks 40 years since the United States ended the military draft, and an ever smaller slice of the population appears to share Majetich’s belief, however. Statistics are rare, but a Department of Defense 2011 Status of Forces survey indicated that 57 percent of active troops today are the children of current or former active or reserve members of the armed forces.

A recent Gallup poll showed that despite the wars in Iraq and Afghanistan, a much smaller percentage of those who’ve reached military age since Sept. 11, 2001, have served than in previous decades.

Part of it is simple demographics. While the U.S. population has grown since the draft ended in 1973, the military has shrunk. But this all-volunteer force appears to be passing from generation to generation, bringing up the worrying notion that the United States is developing a warrior class.

“The declining veteran population is one of our concerns, since there are fewer young adults in American society who are exposed to military service,” said Lt. Cmdr. Nate Christensen, a Pentagon spokesman. “While the armed forces continue to be largely representative of the country as a whole, nearly four decades of an all-volunteer force has shaped who is most likely to serve and from where.”

In the wide halls of the Pentagon, the military often is referred to as “the world’s largest family business.” The fear among some military leaders, politicians and experts begins with the belief that as fewer segments of society have family or friends in uniform, others become desensitized to the risks and stresses of military service. The feared risks range from a reluctance to fully support those who serve to an almost cavalier willingness to wage war, reasoning, “That’s what THEY signed up for.”

Historically, problems with such classes have ranged from the military having too much influence in all walks of society – Prussian officers collected taxes – to being marginalized, as with the so-called “barbarization” of the Roman military, which relied heavily on non-Romans.

Sen. James Inhofe, an Oklahoma Republican, has spent decades voicing such fears. He’s one of the few politicians around who still yearn for a draft.

“Now, we’re never going to get the draft back,” he said. “But I really believe the greatest risk isn’t to the military and the few who serve, it’s to the rest of society.”

Inhofe thinks that military service makes better citizens. The broader the base of volunteers, he said, the better.