Extremism? "Nationalism"? Free Speech?

Andrew Dyer of the San Diego Union-Tribune reports here on the Marine Corps' investigation of a lance corporal who "describes himself on his Twitter account as a 'nationalist' and says he is the chairman of a group called the 'U.S. Nationalist Initiative.' Its Facebook page has more than 1,400 followers."

What would you do if you were the commanding general or staff judge advocate? Grounds for separation?

H/T to Task & Purpose for the link.