Turkey jumps in WW1! Why?

at the turn of 1914, British Naval Mission was led by Admiral Limpus, French Gendarmerie Mission led by General Moujen, and German Military Mission existed. Among these three, German Military Mission become the most important as the command center of the Ottoman military, the Sultan, Minister of War, and Head of German Mission developed extensive relations. The history of these relations went back to 1912, Grand Vizier the Sait Halim Pasha and Minister of War Ahmet Izzet Pasha. Kaiser Wilhelm II ordered General Goltz to establish the initial mission, which served two periods in within two years. In the early 1914, the Minister of War Enver Pasha, a former military attache to Berlin was at the helm, and that, at about the same time, General Liman von Sanders, a German general, was nominated to the command of the 1st Army. 1st Army was the biggest which was located in the Europan side. General Liman von Sanders and Enver Pasha practically shared the commander-in-chief position.
World War I, 1914–18: Brittanica
The Ottoman entry into World War I resulted from an overly hasty calculation of likely advantage. German influence was strong but not decisive; Germany's trade with the Ottomans still lagged behind that of Britain, France, and Austria, and its investments, which included the Baghdad railway, were smaller than those of France. A mission to Turkey led by the German military officer Otto Liman vonSanders in 1913 was only one of a series of German military missions, and Liman's authority to control the Ottoman army was much more limited than contemporaries supposed. Except for the interest of Russia in Istanbul and the Straits, no European power had genuinely vital interests in the Ottoman Empire. The Ottomans might have remained neutral, as a majority of the cabinet wished, at least until the situation became clearer. But the opportunism of the minister of war Enver Paşa, early German victories, friction with theTriple Entente (France, Russia, and Great Britain) arising out of the shelter given by the Ottomans to German warships, and long-standing hostility to Russia combined to produce an Ottoman bombardment of the Russian Black Sea ports (Oct. 29, 1914) and a declaration of war by the Entente against the Ottoman Empire.