No dog left behind. That's the motto one U.S. soldier had for canine friend he met in Afghanistan.

Phil Bourillion serves on the U.S. Army Striker team. The unit took in a malnourished puppy they found on the side of a road.

But when the team received new orders they were not allowed to take little Oso with them, that's when Phil, with the help of his wife Lena, started a secret mission to get the dog to the U.S.

They paid a driver to sneak him across enemy lines. Then got him smuggled into Pakistan. From there Oso boarded a Delta plane headed for America.

"She was such a monumental part of their lives and what she provided for love and happiness there to them," Lena said. "You can't let them down."

"Boost to morale when we had her," Phil said. "We raised her from nothing. We loved her."

The whole ordeal took more than two months, not to mention 50 hours of flight time for Oso.