If a US protester been called to testified at the UN Security Council against allegations of US war crimes in Vietnam

Emerging from the environment in Madison Wisconsin of mass protests against the Vietnam War 46 years ago, before moving to Israel, I wonder what would have been the response of the US public had one US protester been called to testified at the UN Security Council against allegations of US war crimes in Vietnam. Such a tactic was unthought of. If it had been implemented, it would have evoked cries of treason.