It could be argued that once Germany was divided into East and West following the end of WW2, East Germany was severely underdeveloped.

The Soviet Military Administration (SMAD) in East Germany refused to take part in the USA's Marshall Plan - which aimed at rebuilding the devastated countries of Europe.

It took a long time for East Germany to recover after the war, so much so that many East Germans tried to leave for the West - prompting the Berlin Wall to be built.