There are significant differences of history, culture, and politics (and more) across nations – differences that make it unadvisable for leftists to try to mechanistically and simplistically “plug in” lessons from one nation, place, and time to another nation, place, and time – from, say, Czarist Russia, Mao’s China, or the French Third Republic to the contemporary United States.  Still, the sum total of left-progressive lessons in any one nation and period is hardly gleaned from that nation and time alone. U.S. progressives can garner useful knowledge and cues from other times and/or places in the existentially imperative task of trying to build a relevant left[1]and then a democratic, just, and sustainable society in the U.S….read further