Russian communists were internationalists and wanted a world revolution. That's why they supported left-wing movements throughout the world, and that's why Moscow has numerous places named like Patrice Lumumba University or Martin Luther King Square (no kidding). The idea of peaceful coexistence with the capitalist West became acceptable only after most of the killings were finished.

The single-point-of-failure word you're looking for isn't "nationalism", it's more like "ideology" or "mass movement". Read Eric Hoffer's "The True Believer" for more.