April 6, 1917, the United States joined England, France, and Russia in the war against Germany (and Austria-Hungary). Michael Kazin, professor of history at Gerogetown, has a book exploring why we shouldn't have done it. Marking the anniversary, the NYTimes has a short op-ed piece by Kazin making the case against U.S. intervention. As we now see WWI and our decision to enter set off many of the tragic consequences still playing out in Europe and the Middle East.
Kazin: "America’s decision to join the Allies was a turning point in world
history. It altered the fortunes of the war and the course of the 20th
century — and not necessarily for the better. Its entry most likely
foreclosed the possibility of a negotiated peace among belligerent
powers that were exhausted from years mired in trench warfare."