June 28,Assassination of the Archduke Franz Ferdinand & his wife, Duchess Sophie.
Austria sends an ultimatum to Serbia. Serbia would meet most but not all of the demands.
Austria declares war & Russia mobilizes in support of Serbia. Mobilization was the same as declaring war.
Once armies started they could not be stopped without upsetting all the plans.
Germany declared war on Russia.
Under agreement France had to help Russia so Germany was also at war with France. Germany now had enemies on two fronts.
Britain agrees to support France.
Germany enters Belgium.
Britain declares war on Germany because Germany had entered Belgium.
Italy switches to Entente because she claims not defensive so the Alliance did not hold.
The Entente promised her land if she switched sides.
From 1914-1918,
12,000,000 soldiers would be killed.
WME
The War to End All Wars