Churchill didn't go back far enough. It went back to the Treaty of Versailles when the "winners" decided a starving Germany had to pay for a war that the Allies gleefully decided would end by Christmas 1914. They then decided to carve up European nations that had existed for literally centuries. They also vastly underestimated the new weapons of war each nation decided to invest in before the war, and fought the battles as they had back during the Napoleonic era - which ended with the slaughter of millions of soldiers on both sides.