Dishonorable discharge

Under UCMJ, desertion carries the death penalty. But reduction in rank and 25 years in the stockade ought to be enough.

By the way, even though it's clear that President Barack Obama was born in Hawaii, I would assert that he is a natural born citizen no matter where he was born because his mother was a citizen at the time of his birth. And there's no explication of the phrase nor any case law to contradict me.