Indeed, my mother visited Berlin during the 60s or 70s and was surprised by how many buildings lay in ruin or bore obvious marks of the war. Warsaw was immacula

Indeed, my mother visited Berlin during the 60s or 70s and was surprised by how many buildings lay in ruin or bore obvious marks of the war. Warsaw was immaculate by comparison. (For those who don't know, Warsaw was intentionally flattened by the Germans in almost its entirety.) Most of the rubble had been cleared away and much of the city had been rebuilt, albeit according to new socialist principles and styles. Only a fraction of the pre-war architecture was rebuilt (most famously the Old Town). I'm sure a difference in politics in both cities played a role—the communist regime in Poland had been the most "liberal" of the Eastern Bloc—but I don't know for certain what the exact causes were.