The high-principled and idealistic Woodrow Wilson was President of the United States between 1912 and 1920 and initially sought to avoid American involvement in the First World War.
The US declared its neutrality on 19 August 1914. Wilson was personally appalled by the evil of war and his faith in the processes of international justice committed him from the outset to an active role as mediator.
A series of diplomatic missions to belligerents between 1914 and 1916 was undertaken by his personal emissary Colonel House, in an attempt to seek a negotiated settlement. All failed, primarily because the warring nations were ultimately unwilling to compromise their mutually exclusive war aims.
Wilson's role as an impartial mediator was also compromised by the war's effects on his own country. The US economy benefitted hugely from supplying munitions and foodstuffs to the warring nation, but in so doing US ships became casualties of the war at sea.
Wilson's exasperation with Britain over the Royal Navy's searching of neutral vessels was completely overshadowed by the devastating effects of Germany's unrestricted submarine war against neutral shipping – the ultimate consequence of which was the US declaration of war against Germany on 6 April 1917.
Wilson proved a decisive and forceful wartime leader, but despite his legal fair-mindedness and committee skills, the post-war Versailles Peace settlement proved an unhappy compromise. The US Congress rejected the treaty, including membership in the League of Nations, Wilson's own proposed ideal institution for settling international disputes.