Complex sentence: Finally, the isolation of Syria in the past few decades further exacerbated the situation, although perhaps it is this very decline that has helped to preserve the old city of Aleppo, its medieval architecture and traditional heritage.
Split into simpler sentences: Finally, the isolation of Syria in the past few decades further exacerbated the situation. This decline may have helped to preserve the old city of Aleppo, its medieval architecture and traditional heritage.