World war one was the Great War, the War to End all Wars, the Liars War. More and better liars were told, than all the american wars combined, including Vietnam.
First, the US was not neutral. In 1914 the British Army needed 3 million riffles. Guess were they got them. Enfield peddler rifles were manufactured in the US, shipped to Britain as "parts" and assembled with a screw driver. By January 1917 the US was providing half of all French TNT, and most of the steel for the French armament industry. Plus food for British and French workers. US banks and investors held 1/3 of all allied war debt. None of this was in the newspapers at the time.
The British and French press lords did the greatest service new paper men could ever do for their country. They Lied like dogs. In Germany the press was controlled, so nobody believed them. But Britain and France had the freest press in the world, everyone believed them, and they lied just about everything. The Entente would have lost the first year, if not for the press.
The British and French press lords did a deal deal with american newspapers. You report the war as we tell you, or we will cut you off from all news, and get your advertisers who are making tons of money off this to cut you off as well. Who would buy a newspaper with two week old news, so almost everyone fell into line. The fact the Lusitania was blown up 20 feet out of the water before she sank was hidden.
The press was so good, even the French and British generals believed it. Why do you think they kept on attacking in a suicidal way. Because according to the newspaper reports, the attacks were brilliant. One more push and it's on to Berlin.
As late as the 1970's, american high school history books repeated allied propaganda. The fact is the Germans were slaughtering allied soldiers at a rate of three to one for most of the war.
The French viewpoint is based on the fact that France would have been beaten with out the British and the Americans. Things were so bad, the French put Marshall Petain in charge, the only senior general who studied the american civil war. Petain rejected all military doctrine, because it did not work, and developed new tactics at Verdun, which took the British two years to adopt.
An interesting point. Most american officers studied the Franco Prussian war in collage. Most German officers studied the american civil war in collage. But the French and British did not study the american civil war in collage. In 1914 only two countries had modern artillery schools, Germany and the US. and most of the american text books were ripped off from the Germans.