Complex sentence: Murad II was in no position to stop these troublesome westerners since he was overwhelmed with problems by easterners in Anatolia, the core of the Ottoman realm and so hastily concluded a peace treaty in the Balkans.
Split into simpler sentences: Murad II was in no position to stop these troublesome westerners since he was overwhelmed with problems by easterners in Anatolia, the core of the Ottoman realm. Therefore, Murad hastily concluded a peace treaty in the Balkans.