> Something tells me that the anti-NATO folks on the Far Left who hold ineffective anti-war rallies don't understand the need for the threat of force if agreements aren't followed.
As Putin's recent addresses have been denouncing gays in the West, and the vast majority of conservative republicans to liberal democrats in the US congress have voted to send more arms to the Ukraine, I suppose the provenance of peace in this conflict is, as you say, on what is called the "Far Left".
Whether anti-war rallies are ineffective or not I can not say. The lowest estimate for the London anti-war rally in 2003 was 750,000 people. In my experience when more than 750,000 show up against something it has a political effect. Of course rallies and marches alone do not change things, a sustained campaign of education, organization and agitation is needed. Historical records show the anti-war movement during the Vietnam War had political effects in preventing escalation.
There is the far left, and there are architects of the Vietnam War like Robert McNamara, who was Secretary of Defense during the Cuban Missile Crisis. He spent his retirement warning of the dangers of a small conflict between major powers spiraling into a full-scale nuclear conflict, and that it was something that could happen, he was in the room when these decisions were made and he helped craft these decisions. Not a far left view, but a Republican Ford CEO who worked to crush the Cuban and Vietnamese revolutions.
The point being there is danger on either side. Nuclear proliferation and escalation seems more dangerous than moves toward disarmament to me. Nowadays the US, UK, France, Russia, China, India, Israel, Pakistan and North Korea are all members of the nuclear club. And Russia and China both have significant nuclear triangle capabilities.
In a class-based society of nation states, where idle class heirs expropriate surplus labor time from wage workers, over a long enough timeline, a war involving nuclear weapons seems an inevitably.