The West has been destroying itself lately, imagine if the Soviets could take advantage of it
China, and truthfully most east asian socialist projects, are far more nationalist (and in some ways ethno-nationalist) than any of the european/american/african socialist projects were. The lines drawn for these countries tended to always be different than it was for the USSR and other allies (like cuba is a fairly diverse country already, and that made it easier to adopt a culture of internationalism).