Bill Laurie Ph.D Historian: This is hardly news. See article at link below. There is no hiding close cooperation between "anti-war" elements in U.S. and Hanoi legions. They weren't truly "anti-war" as much as they were "pro-Hanoi's-war."
Though a "friendly" objective commentary this article is full of huge errors and omissions. Author never mentions Hanoi's setting up communist governments in Laos, Cambodia. Next, there was no "cease-fire" in '73 and Hanoi's war kept rolling along. There was no "suddenly" in '75 collapse as RVNAF and GVN had been bludgeoned and hammered for two years, and RVNAF supplies and munitions were cut 90% not 50%. The VC were not "allied with" but entirely a creature of and subordinate to Hanoi's communist party.