No, for assistance to an enemy to be treasonable, war must actually have been declared, and only Congress can declare war. Actually waging war on the US is treasonable without a Congressional declaration, but the definition depends on a state of "open war" in which you're part of a recognized assembled group of people engaged in open armed hostilities. The short answer to almost all these kinds of questions is "it's…
I'm trying to parse this.
Waging war on behalf of the US?