The United Kingdom had hoped that strategic considerations might persuade Constantine to join the cause of the Allies, but the King and his supporters insisted on strict neutrality, especially whilst the outcome of the conflict was hard to predict. In addition, family ties and emotional attachments made it difficult for Constantine to decide which side to support during World War I. The King's dilemma was further increased when the Ottomans and the Bulgarians, both having grievances and aspirations against the Greek Kingdom, joined the Central Powers.