No, the largest reveal of major military secrets to the Russians was... the Walker family. Our entire SOSUS underwater listening system, and many other way huge technical advantages we had were exposed by daddy Walker, and his family and buddy. Senior Walker did it for money— big time swinger that he was. A real a@@hole.
And he and his older brother, who helped him— both died of cancer at Butner Federal Correctional in NC (same place that Bernie Madoff is serving 150 year sentence).
This a@@hole Walker did all this damage- putting the US in serious exposure to Russian attack during the Soviet era. Snowden’s reveals...reveals the Cheneys, and Bushies and corrupt Mueller=crats of the highly profitable derp state.
The Walkers— all US Submariners (veterans and serving) know who and what he was. Most would have gladly shot him in the head. His own son, his older brother, and a guy still alive named Whitworth serving his life term in Colorado, still.
Walker:https://en.wikipedia.org/wiki/John_Anthony_Walker
Probably the most serious reveal of military secrets was the Clinton crime family. Of course, the Clinton crime family was sophisticated enough to legally transfer military technology.