Privacy

Yep, which is why there's only ever been ~40 treason cases in the history of the US. It was very intentionally made nearly impossible to prove, to prevent it being abused for political reasons. It was considered extremely important to have a strict definition to prevent accusations of treason being casually used to describe an act by a political opponent. Also this is a decent example of why the US hasn't formally declared war in so long - many things are only possible under a declaration of war, almost all of them both politically and socially horrible. It's been in everyone's best interests to not open that particular avenue of abuse as a result.