The officials said the Pentagon’s top leaders are now scrambling for ways to find new recruits to fill out the ranks of the all-volunteer force. Defense Secretary Lloyd Austin and Deputy Secretary of Defense Kathleen Hicks consider the shortfall a serious issue, said the officials, and have been meeting on it frequently with other leaders.

“This is the start of a long drought for military recruiting,” said Ret. Lt. Gen. Thomas Spoehr of the Heritage Foundation, a think tank. He said the military has not had such a hard time signing recruits since 1973, the year the U.S. left Vietnam and the draft officially ended. Spoehr said he does not believe a revival of the draft is imminent, but “2022 is the year we question the sustainability of the all-volunteer force.”

The pool of those eligible to join the military continues to shrink, with more young men and women than ever disqualified for obesity, drug use or criminal records. Last month, Army Chief of Staff Gen. James McConville testified before Congress that only 23% of Americans ages 17-24 are qualified to serve without a waiver to join, down from 29% in recent years.