The Pentagon has seen early success in signing up green card-holding legal immigrants with the promise of immediate citizenship as a solution to a recruitment nightmare that threatens to cripple its ranks as early as 2025.

"The Biden administration still requires people to have a green card to join the military, but they're overwhelmed with people who want to join the military and cannot because they don't have a green card," said Margaret Stock, a retired lieutenant colonel in the Army Reserve and author of Immigration Law and the Military: Army, Navy, Air Force, Marine Corps, Coast Guard.

Facing major recruitment shortfalls this year, the Army and Air Force chose, over the past nine months, to broaden their appeal to legal permanent residents, otherwise known as green-card holders, and partnered with the U.S. Citizenship and Immigration Services to guarantee that people who successfully complete basic training will be sworn in as U.S. citizen service members.

Early results indicate it is working and could do even more to benefit the United States if it is further expanded as it was 15 years ago.