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March 11, 1917
British capture Baghdad -
January 31, 1917
Germany announces unrestricted submarine warfare -
February 3, 1917
US severs diplomatic ties with Germany -
February 24, 1917
Zimmermann Telegram is passed to the US by Britain, detailing alleged German proposal of an alliance with Mexico against the US -
February 26, 1917
US President Woodrow Wilson requests permission from Congress to arm US merchantmen -
March 20, 1917
US President Woodrow Wilson's war cabinet votes unanimously in favour of declaring war on Germany -
April 6, 1917
US declares war on Germany -
April 9-20, 1917
Nivelle Offensive (Second Battle of Aisne, Third Battle of Champagne) ends in French failure -
May 12 - October 24, 1917
10th, 11th and 12th Battles of Isonzo fought, ending in Italian failure -
December 22, 1917
Russia opens separate peace negotiations with Germany
