He stole and released critical intelligence that could result in harming diplomatic relations, and put American soldiers lives at risk during wartime (which is aiding and abetting the enemy).  He intentionally violated the Espionage Act, and as someone with a security clearance, he knew the risks. Violation of the Espionage Act carries with it a penalty of death.

If he was unprepared to accept those consequences, he should've kept his treasonous mouth shut.