U.S. intervention in the war became deeply unpopular following the signing of the armistice. This became very obvious with the Senate’s rejection of the Versailles Treaty and Wilson’s League of Nations idea. Congress took this a step further by passing laws aimed at preserving U.S. neutrality in the future. Polls taken right before the outbreak of World War II showed that a majority of Americans still viewed intervention as a mistake. This did change once France had fallen to Germany in 1940. So as far as global democracy is concerned, the Senate’s rejected of the treaty did not make the world safer for democracy.
In the years following the war, many began to question why we had gone to war in the first place. Wilson’s insistance that it was our moral duty as a nation began to be scrutinized. One school of thought was that bankers, who held more than $3 million in Allied war debt, were worried they would not get paid if the Central powers won, and used their moneyed interest to force the U.S. into the war. If this is true, than the war did not make the world safer for democracy, just safer for banks and those holding bank receipts.
And of course the fact that Germany was saddled with all the war debt meant that the rise of fascism was insured, and that certainly didn’t make the world safer for democracy.