Well covered. I suggest adding something about the Zimmerman telegram in the part about US neutrality. Germany was shipping arms to and trying to get Mexico to ally with them against the US. It was that decoded telegram more than the Lusitania that triggered Wilson to get into Europe's bloodfest. Don't forget the US (Patton) was busy hunting Pancho Villa, and the US also sent troops into Russia to "protect American interests" during the communist takeover (and Russia still hates us for that).