David Chu, undersecretary of Defense for personnel and readiness, and other military and data analysts discussed the issue Thursday at the Heritage Foundation, the Times reported.

The longevity of the Iraq war, a negative view of military life and rising obesity rates nationwide were cited as principal reasons for the decline, the Times noted.

About a third of potential military recruits are rejected because of an inability to meet physical standards, according to Department of Defense material presented by Chu, the paper reported.

Lawrence Kapp, a specialist in military manpower policy for the Congressional Research Service, said it is difficult to convince high school graduates that the military is a viable and worthy endeavor. CRS studies reveal a large number of people with the "propensity to enlist," but 85 percent of them don't, according to the Times.

"Enlistment in the military carries a connotation of a kind of blue-collar position," he said.

Kapp told the gathering, however, that higher standards for enlistment have produced a military that is highly qualified and more educated than the rest of the U.S. population. About 97 percent of military recruits have high school diplomas, compared with roughly 80 percent in the general population, according to his department's studies.

"There has to be some way to reconnect military service with the white-collar expectation of some of the youth today," he said.

Learn more about Prior Service bonuses.