[Sherman Logan]

Trotsky was a military genius, but I think the chance of his conquering Europe if not stopped at Warsaw ranged from zero to less than that.

There was very little support among “the proletariat” of the nations of Europe for a Russian-led socialist revolution, and his invasion of Poland collapsed largely because of his distance from his base.

[Cronos]

From what I read in Zamoyski, the proletariat did support the Russians. Perhaps not for a socialist revolution, but one pushed by an external impetus could have worked

his failure in Poland was due to Stalin actively working against him with Budyonny