But in your case, I believe your conduct in putting into the hands of the Russians the A-bomb years before our best scientists predicted Russia would perfect the bomb has already caused, in my opinion, the Communist aggression in Korea, with the resultant casualties exceeding 50,000 and who knows but that millions more of innocent people may pay the price of your treason.
It's not however the crime of treason as defined under US law.
18 U.S. Code § 2381 - Treason
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 and shall suffer death, or shall be imprisoned not less than five years and fined under this title but not less than $10,000; and shall be incapable of holding any office under the United States.
If enemies of United States were behind this assassination attempt, and Cheatle facilitated their plans, then a case can be made that the act is Treason.
Judge made it clear that what they did was Treason
https://web.archive.org/web/20080702015209/http://www.law.umkc.edu/faculty/projects/ftrials/rosenb/ROS_SENT.HTM
If enemies of United States were behind this assassination attempt, and Cheatle facilitated their plans, then a case can be made that the act is Treason.