Can anyone explain the difference between leaking classified information where the information leaked doesn't technically violate any laws (ie- wikileaks) & printing something like the drone report (drones violate international law but we knew that before the papers) and actually whistleblowing like cigarette companies have been using carcinogens or NSA violating American rights. The first two are treason, but the latter two are whistleblowing? Does what is reported actually matter to avoid a treason charge?
"Whistleblowing" by publicizing classified information does not have a safe harbor in the law. In the U.S., everyone who is given access to classified information signs NDAs acknowledging that unauthorized disclosure of classified information will subject them to both civil and criminal penalties. (Even non-government NDAs subject violators to civil penalties, unless used to report a crime.)
Granted: no contract can be used to punish someone for reporting a crime. But there are means to report crimes one sees in classified information without breaking the law.
If one believes that classified information showing law-breaking is being tolerated "all the way to the top" then, in principle, one would have to take one's allegations public, which does violate the law. Of course, such legitimate disclosures become highly politicized. If the "whistleblower" in such a case is actually charged then he can ask for a jury trial and try to convince the jury that breaking the law was justified, or even morally necessary.
"Treason" is just one of the more severe crimes you can face for "whistleblowing" by injudiciously disclosing particularly sensitive classified information. The elements of treason are very simple. From 18 USC 115:
Whoever, owing allegiance to the United States, levies war against them or adheres to their enemies, giving them aid and comfort within the United States or elsewhere, is guilty of treason....