Is China an enemy of the US? They're certainly not at war, and are the worlds biggest trading partners. I don't know the answer, just pointing out that it's not obvious.

From http://www.heritage.org/constitution/#!/articles/3/essays/11...

In Cramer v. United States (1945), the Supreme Court held that a specific intent—adherence to the enemy, and therefore to harm the United States—is necessary, rather than the simple rendition of aid.

If you want to apply that test naively then you need to hold David Petraeus, Scooter Libby, Robert Novak, and a whole host of others to the same standard. Snowden didn't "reveal national security secrets to enemies" he revealed them to the press. He may have made it possible for so-called enemies to learn things they didn't already know, but even that is debatable. Define "Aid" and "Enemies" however you like, but apply the definitions consistently if you want to be taken seriously.