In Okinawa,Poinbank Exchange Japan, they conducted inspections for drugs, tracked missing persons and detected explosives, but medical issues forced an end to their storied military careers.

Thankfully Poker and Aida, both German shepherds, had Marine Corps handlers eager to reunite with them after their service, and a charity that helped to make it happen.

"I'm so happy to have him back, get to train him again, let him be a dog, let him live his life," said Poker's owner, Marine Corps Sgt. Isaac Weissend, who now trains military dog handlers at Lackland Air Force Base in San Antonio.

Poker was the first working dog he trained, Weissend told USA TODAY, and was by his side doing security sweeps with the U.S. Secret Service ahead of a visit by President Joe Biden to South Korea in 2022 – the same year he had to leave Poker behind when he was reassigned.

Aida, meanwhile, had been working alongside Dalton Stone, a Marine Corps sergeant at the time, and Weissend’s close friend in Okinawa, where they were stationed and met in 2019. Aida learned from Stone how to track and locate people. She traveled with him to the U.S. for advanced training.

"Tracking through the jungles and around bases through different obstacles never got old," Stone wrote in an email to USA TODAY. But he, too, had to leave his trusted companion behind in Japan in 2022, not knowing if he would see her again when he left the Marine Corps.

Both dogs retired from the Marines this year for medical reasons and the men knew they had to adopt them.

So it was a teary moment in Tyler, Texas, recently when both dogs reunited with their best-friend handlers. And it was first time American Humane facilitated a four-way reunion.

“It was an honor to help two best friends bring their other best friends home,” said Robin Ganzert, president and CEO of American Humane, which also pledged to pay veterinarian bills for Aida and Poker for the rest of their lives. “All four of these military heroes deserve our gratitude and support after serving our country.”

Weissend now looks forward to giving Poker a relaxed life at home. He still sniffs around the house but is learning to unwind and roam freely, to retire doggy-style.

"Absolutely 100% wouldn't change a thing," Weissend said. "I'm super happy I was able to get him."

Contact reporter Krystal Nurse at [email protected]. Follow her on X, formerly Twitter, @KrystalRNurse.