"Trianon", the peace treaty which officially ended the First World War for Hungary, signed in Versailles in the Trianon Castle on the 4th of June, 1920, is one of the most catastrophic events in the history of the Hungarian Nation. With this "treaty", the Allies or more commonly the 'Entente' implemented the decision by which Historic Hungary was dismembered. This is how, under the pretext of founding new nations, the largest minority group in Europe, the Hungarian minority, was created.
This decision, which was made without hearing Hungary's argument, forced 3.2 million Hungarians to live in other countries, suffering scorn and discrimination.
This decision was made in spite of the fact that almost all territories inhabited by Hungarians could have been left within the borders. The territories with the largest Hungarian minority are situated in a bloc just outside the present borders. Transylvania is the only exception, with communities that are farther from the borders and there are many areas still populated by pure, ethnic Hungarians.
The new borders, imposed by the treaty, had a "more far-reaching" effect than the dismemberment of the Hungarian nation: this decision sowed the seeds of the outbreak of the Second World War. It increased tension between Hungary and its 3 neighbours: Czechoslovakia, Romania, and the Serbian-Croatian-Slovenian Kingdom (Yugoslavia) to the bitter end. At the same time, this created an opportunity for Germany, led by Hitler, to take advantage of these conflicts of interests in order to use them for its own purposes.
That this devastating effect could have been predicted is proved by Premier Károly Huszár's speech, January 1920: "What is waiting for us will decide not only the Hungarians' fate, but it will also mean the permanence of Europe's peace. A just peace will mean peace and safety for the European civilization, but an unjust one will be a newer suicidal attempt for Europe's peace."
Certainly, these considerations were not taken into account at the decision-making. The main purpose was to fulfill the demands of the 3 previously mentioned neighbouring countries and, by this, to assure their long-standing Entente-friendly policy, which later proved to be unsuccessful. They also wanted to make the economic recovery of Hungary more difficult.