KANSAS CITY, Mo. — Chalk up another national-security threat — this one looming with each excess pound, failing grade and drug bust affecting young adults.

An alarming 75 percent of Americans ages 17 to 24 would not qualify for military service today because they are physically unfit, failed to finish high school or have criminal records. So says a new report from an organization of education and military leaders calling for immediate action on the early-education front.

While some experts voiced doubt that obesity and other societal ills would keep three out of four young adults out of the ranks, the report titled "Ready, Willing and Unable to Serve" was endorsed by U.S. Education Secretary Arne Duncan, former NATO commander Gen. Wesley Clark and top retired admirals and generals.

"The armed services are meeting recruitment targets in 2009, but those of us who have served in command roles are worried about the trends we see," retired Rear Adm. James Barnett said. "Our national security in the year 2030 is absolutely dependent on what's going on in kindergarten today."

Military recruiters in Kansas City report turning away prospective recruits "in every office, every hour, every day" for reasons including girths too large and credit ratings too low.

Increasingly, applicants are disqualified for having asthma or for taking pills for depression or attention disorders. Nearly one-third of all young adults have health issues other than weight that could keep them from serving, according to the report of the group Mission: Readiness.

If you're the single parent of a dependent child without a support network, you're out. If you're carrying too much debt, you're out. The military doesn't want recruits who will be hounded by creditors and lawsuits.

Some applicants without a high-school diploma can get a waiver to serve if they earn a GED or score high on the military's entrance exam. But such waivers are granted to fewer than 2 percent of applicants.

"What we allow waivers for, and for whom, is like an opening and closing gate depending on our needs. We can adjust our policies if we have to," said Douglas Smith of the U.S. Army Recruiting Command.

As a slumping economy increases interest in military service, more people with obvious deficiencies are contacting recruiters.

"We're no longer so much saying, 'Try back in 60, 90 days and see if you can qualify,' " Smith said. "It's more like 'We're sorry ... and don't come back.' "

Even after signing up, 7 to 15 percent of enlistees return home for not meeting all that basic training demands.