WWI ends in a draw, but only after slaughters comparable to those of OTL.
On the western Front the German Army remains undefeated, but Russia is already in revolution and the Ottomans are even more badly mauled outside the European continent, where not even a undefeated Germany can help. Kemal Atatürk chokes in a shish-kebab in 1918, and the campaign to expell the Greeks from the Agean coast fails utterly, the Greeks "liberating" Istanbul in 1921 and proclaiming the rebirth of the Byzantine Empire. A-H doesn't survive the armistice by many months before dissolving in ethnic unrest. The Hungarians secure a large chunk for themselves as does Italy, while the rest finds their own identity. Some years after Austria is amalgated with Germany after a referendum. The Germans can however resist Danish demands for a referendum in Schleswig, and the border from 1864 remains intact.
The Revolution in Russia has communists in power in Russia itself but "whites" in the smaller states in the western parts of the former Russian Empire.
The feeling of having fought for years without achieveing anything leads to unrest all over Europe, and at least temporaily weakens many ruling systems. In UK this eventually (1920's) has Ireland (Eire?) achieve independency.
Communist unrest soon spread to countries not involved in WWI, and in Spain the civil war of the 1930's ends with republican Catalonia seperating from nationalist Spain.
In Germany the Kaiser remains in power, but the socialdemocrats with increasing success limits his power - and the navy budgets. The real breakthrough is when capital realises, that socialdemocrats are the best defense against communists, and the Army is assured that it is only the navy that is to be reduced. Wilhelm dies in 1941 as a symbolic but loved figurehead.
In 1939 Stalin has a go at Finland, but in this TL Finland is swiftly supported by Germany, UK and the Scandinavian countries and the Russians are even more badly mauled. After Leningrad has fallen to the Finish Army and the International Expeditionary Force in early 1940 Stalin is assassinated and SU falls into chaos. Finland keeps large areas occupied, incl. Leningrad, and after a decade of famine in Russia the remaining Russians in the Finish occupied areas happily vote for joining Finland in 1953. Russia is by late 50's and still today ruled by a theocracy with the Patriarch of Moscow being the real ruler. It is stable, people are fed, clad and drunk, it's strong enough to keep enemies out, but it is terribly backward, hardly ever sober and no big threat to anybody outside Russia. A lot of Russians, not at least those not being Orthodox or alcoholic, flee Russia and the progromes and most arrive in USA.
France stays in almost permanent chaos after the anticlimax of suffering so much and gaining nothing in WWI. French nationalism soon reach strident levels, and one of the main conflict lines shows up in Belgium, where the French speaking Wallonians are spured into seeing the Flemish as devils. In 1968 large demonstrations in Paris, lead by students from Sorbonne, demands that the government intervene in Belgium. Soon French troops roll over the border to Belgium and reports of attrocities aimed at the Flemish soon flash the news all over the world. The Dutch, British and German governments demand that the French withdraw. The French reply something like: "We will fart in your general direction, and your mother was a hamster!"
Soon the "War of 68" is a reality. German and Dutch troops liberate Belgium while the British hauls down the Tricolore at various places outside Europe and hoists the Union Jack. In the peace agreement Belgium is transformed into a Dutch protectorate, while France falls into an even deeper depression, mentally and economically. By early 2005 the Belgiums happily vote for a "Leningrad II" joining the Dutch.
In 1995 a demand from Faroe Island for more government grants is sent to Copenhagen, and is followed by a: "...or else we want independence!". Soon a letter from Copenhagen is issued to all households on the Faroe Islands, it goes like this:
"Dear Faroe Islanders
We have been together for centuries, but everything has an end, and so does our union. The Inspection Ship Beskytteren will therefore leave Thorshavn next Tuesday at 1200 bringing with it Danish moveables and officials. If you would like to leave too, you can que up at the quay, and we take as many onboard as space allows. The rest will have to seek asylum.
Bye bye
Margrethe II, Queen"
This immediately has the Faroe Islands enter a severe economic crisis, but by 2001 a union with Iceland is concluded however. In Copenhagen Danish officials do note, that the Greenlanders are remarkably easy and not very demanding to negotiate with about government grants.
USA never really got involved in WWI, and tried to forget that they formally had declared war on Germany in April 1917 - it obviously didn't work to intervene across the Atlantic. That pretty much sets the standards of US foreign policy for the next century. USA thrives economically and culturally and still has a large influx of European immigrants, not at least Russian Jews and intelectuals, and later also a lot of Frenchmen. Some Americans advocates that USA should actively fight the huge British Empire, but Congress never really wants to grant money for the forces needed for such an adventure. Japan has been a concern a couple of times, but the British Empire has each time tackled it before it became serious, and other Americans remarked that as it was the RN that maintained the Monroe Doctrine in the 19th century in the Atlantic, it was the same in the Pacific in the 20th, and that really was an advantageous solution for the US taxpayers.
Regards
Steffen Redbeard