Guess he was too stupid to realize that there are other foreign legions.
Spanish Legion
http://en.wikipedia.org/wiki/Spanish_Legion
Russia’s new Foreign Legion
http://themoscownews.com/news/20101125/188233351.html
Foreign Militaries That Accept US Citizens
http://militarycareers.about.com/od/Why-Join-The-Armed-Forces/tp/Foreign-Militaries-That-Accept-Us-Citizens.htm
Why would Bergdahl want to join the French Foreign Legion?
A. For their education benefits in the US.
B. They have a great ballet program.
C. He likes to eat snails.
D. To protect and defend the Constitution of The United States.
E. He’s a dumbass.