I looked up the definition of treason in the constitution and don't quite understand it. One would have to review the documents associated with the debates on the adoption of the constitution and the Federalist papers, and I sure don't have time for that.
But, trading away US foreign policy goodies (like arms, support, assistance, taxpayer money) to a foreign government in exchange for some domestic political advantage sure sounds like:
1) A very bad idea
2) Demonstrative of someone cares about himself, way more than the country.