<They came out of WW II seriously crippled, and didn't receive a Marshall Plan to help them.

Wasn't our fault. I looked it up:

Stalin regarded the plan's vision of an integrated European market with considerable freedom of movement, goods, services, information, and, inevitably, people, as incompatible with his economic, political, and foreign-policy goals.

In 1947, delegates from France, Great Britain, and the Soviet Union met in Paris to discuss the Marshall Plan. After several days, Soviet Foreign Minister Vyacheslav M. Molotov walked out, stating that the Soviet government "rejects this plan as totally unsatisfactory."

Viewed by Western leaders as one more refusal to support postwar stabilization efforts, Molotov's action contributed to the growth of Cold War tensions. In addition to declining to participate in the Marshall Plan itself, the Soviet Union prevented the Eastern European countries under its control from taking part.

Subsequent Soviet propaganda portrayed the plan as an American plot to subjugate Western Europe.

In other words, they turned down the help, because it didn't fit in with their totalitarian vision. Their loss.