He betrayed Clapper and Brennan not the USA. Clapper and Brennan were running the most pervasive domestic illegal spying operation in human history and lying.
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Wikipedia
U.S. U.S. Edward Joseph Snowden (born June 21, 1983) is an American whistleblower who copied and leaked highly classified information from the National Security Agency (NSA) in 2013 when he was a Central Intelligence Agency (CIA) employee and subcontractor.
Snowden was sub-contracted to the NSA from the CIA. The plan was to take down the NSA. CIA was derp controlled (Brennan). NSA was a threat to the CIA and the derp state due to its information gathering programs and a rival of the CIA in that arena.
Trump knows these things. He is likely trying to get Snowden to come in from out of the cold.