Is he being charged with treason? What specific secret information did he expose that the enemy could use against the US?
Jack Douglas Teixeira, a member of the Air National Guard suspected of leaking classified Pentagon documents, was charged in U.S. District Court in Massachusetts on Friday under the Espionage Act and a statute relating to the mishandling of classified documents.
Espionage can become treason when the person involved steals valid information from his own country and gives it to another. Time will tell if the charges are elevated to treason. My guess is that they won't be.
The two charges are for “unauthorized retention and transmission of national defense information” and “unauthorized removal and retention of classified documents or material.”
It is worthwhile to note that these are charges could apply to Trump in that he removed and retained classified documents. No doubt some of the classified documents included national defense information. Last I read, Trump's lawyers still have not used Trump's claim that he declassified all those documents argument in court, probably because they know it won't fly.