So what you're saying is, in the United States "treason" is defined so that a helicopter gunner who murders journalists and unarmed civilians is a hero while the person who exposes this war crime is a traitor.
No, what I'm saying is that murdering journalists and unarmed civilians is not treason, because…it's not.
Now, was the specific act you referred to a war crime, or a case of mistaken identification, or legitimate action against an armed group or individual within a group, or something else? Beats me. It's not my job to decide. Nor was it Manning's job to decide, nor to leak that information because he didn't like the decision of those whose job it was to decide.
It is directly aiding the enemy by giving them a great recruitment tool. A soldier would be hard pressed to find a better recruitment tool to give the enemy.
So fuck 'em, time for others to take on the responsibility.
Manning, Snowden and whoever else in future has access to information that would serve public interest and decides to risk their lives and their freedom to make it known.
They have my full support.
There is a difference between releasing data that is strictly related to the public interest and taking massive amounts of data, including information about very sensitive operations and diplomatic discussions and releasing them without regards to the damage they may cause. It's reckless.
Let's be realistic. This never would have seen the light of day and those involved would never have faced justice.
Manning didn't commit treason either unless he was trying to aid the insurgency, but there is no reason to believe that.