Additionally...
> Free speech doesn't cover the theft of dangerous, classified information and potentially treasonous activities.
Treason [noun]: The crime of betraying one's country, especially by attempting to kill the sovereign or overthrow the government.
He didn't betray his county. He's not a U.S. citizen.
He didn't try to kill any sovereign. The U.S. doesn't have a monarch, and to the best of my knowledge, he hasn't tried to assassinate any sitting president.
There is no evidence that the leaking of evidence of war crimes would overthrow the government. It would probably see a lot of people fired, but given the structure of the U.S. Government, it's nigh on impossible to overthrow a government. Even for something as egregious as war crimes.
So using the word treasonous is a stretch.