The sinking or Lusitania on 7 May 1915 was a significant event during WW1. It was a passenger liner sunk by German submarine during World War 1. It lead to America declaring war on Germany.
By excluding them from the peace process.
A difference between Arab muslim armies and the Ottoman Turk armies on the Byzantine empire was the latter were much better organized and had a much better/well trained standing and professional army which served them well when they were trying to besiege and conquer places in the Byzantine empire.