The heart of the Alt-Left is Antifa (or in full Antifaschistische Aktion). In May 1932, in Germany, the communist paramilitary organisation Rotfrontkämpferbund was banned following a fight between Nazi and communist members in the parliament. Antifa was founded to ensure that the communists still had a militant wing to rival the paramilitary organisations of the Nazis.
From the very beginning, Antifa was a communist movement created by German Communist Party (KPD). A formal announcement of its formation was made in the communist newspaper Rote Fahne in 1932. They held its first rally in Berlin on 10 July 1932, then capital of the Weimar Republic.
While they use their banner of fighting Nazis to imply they were the good guys during World War 2. However, the should not be associated with US/British forces, but rather with the greatest Nazi-killer of the 20th century was Josef Stalin. He also killed millions of his own people and terrorized, oppressed, enslaved, or brutalized tens of millions more. The fact that he killed Nazis during the Second World War (out of self-preservation, not principle) doesn’t dilute his evil one bit.
Antifa are a communist militia in the spirit of Stalin. During the early 1930s Germany, amidst rising tensions between Nazis and the communists, Berlin in particular was the site of regular and often very violent street battles between two armed militias: Nazis and Antifa.
The young Communists and fascists fighting for power in the streets of 1920s Germany had far more in common with each other than they had with decent liberals or conservatives, as we understand those terms today. Their disagreement is over whether to have a globalist or nationalist approach – even Nazis are not nationalist, but racist.
Most tribal hatreds are between very similar groups. The European wars of religion were between peoples who often shared the same language and culture but differed on the correct way to practice the Christian faith. The Sunni–Shia split in the Muslim world is the source of great animosity between very similar peoples. Many — indeed, most — of the great conflicts and hatreds in human history are derived from what Sigmund Freud called the “narcissism of minor differences.”
Today, we see similar violence in places such as Charlottesville, as Antifa fight national socialists for dominance of the political left.