"On (March 1st) in 1917, the text of the so-called Zimmermann Telegram, a message from the German foreign secretary, Arthur Zimmermann, to the German ambassador to Mexico proposing a Mexican-German alliance...is published on the front pages of newspapers across America...Public opinion in the United States now swung firmly toward American entrance into World War I. On April 2, Wilson went before Congress to deliver a message of war. The United States formally entered the conflict four days later."
Of course, Germany never went so far as proposing sending actual troops into Mexico, as many Republicans seem to want to do in Eastern Europe. They just tried to manipulate the country next door into siding with them against us. The Zimmerman telegram was far less of a provocation that what Republicans would do to Russia, yet it led us into World War I. Can you imagine anything short of an all-out attack that would lead the Russian public into virtually unanimous support of Putin's aggression that for their great geopolitical enemy to station troops only a few hundred miles from their soil? Can you think of anything that would do more to justify the long-standing Soviet and now Russian notion that it needed a buffer zone of countries under its control between Russia and Europe?
Republican foreign policy is just as mad and self-destructive as Republican economic and social policy. There is a very good chance that, if Obama had not won in 2012, we would be on the path to World War right now.