Don't blame me, I voted for Hughes!
The Germans were sinking hundreds of American ships before we entered the war 1917. Their aggressive subjugation of Europe and their lunatic Kaiser were unbearable, as were their barbaric cutthroat Ottoman buddies. It was the German Empire which also enabled the Bolshevik Revolution under Lenin. They started a heck of a mess globally. They had to be stopped. The post-war politics and Versailles Treaty were screw-ups however.
Historian Niall Ferguson, now at Harvard, says that the single most catastrophic decision of the 20th Century was Britain's decision to enter WWI. If they hadn't done this, he says, the Germans would have quickly beaten the French and Europe today would be a peaceful continent under benevolent German hegemony, a bit like the EU of today. But no Russian Revolution, communism, Nazism, Holocaust, etc. An interesting thesis. Not sure I agree but he makes an interesting point.