The 60s and 70s were a kind of golden era for leftist revolutionary (or terrorist) groups in the west. It's during this period when you had violent groups like the Weather Underground, the Symbiosis Liberation army, the more radical members of the Black Panthers. In Europe you had the IRA (which had adopted Marxism before its breakup), the Red Army Faction in West Germany, the Revolutionary Cells also in West Germany, the Red Brigades in Italy, the Japanese Red Army and the list goes on and on. All of those organizations carried out a number of high profile bombings, assassinations, highjackings etc against targets in their own countries and internationally.

During the 1960s-70s leftist ideologies were popular with many of the baby boomer generation and there were some key issues for students and young people to focus on, such as the Vietnam War, Palestine and racial oppression in the US. Many of them became radicalized and went on to carry out acts of violence fighting against what they saw are injustices perpetuated by western capitalism in general and the US in particular. This form of radicalism gradually died down as the 70s went on and domestic terrorism in the west shifted from being left-wing to right-wing.