Complex sentence: Following the surrender of Germany, Hansson pushed forwards his will to maintain a Social Democratic-led coalition government of all non-Communist parties, but failed to realize the idea due to strong opposition within his party in favor of a radical reformist agenda following the war.
Split into simpler sentences: Following the surrender of Germany, Hansson wanted to maintain a Social Democratic-led coalition government of all non-Communist parties. However, he failed to achieve this as a result of strong opposition within his own party which favoured a radical reformist agenda following the war.