As it became apparent that the Allied powers would win World War I, nationalist movements, which had previously been calling for a greater degree of autonomy for various areas, started pressing for full independence. The Emperor had lost much of his power to rule, as his realm disintegrated.
As one of his Fourteen Points, President Woodrow Wilson demanded that the nationalities of Austria–Hungary have the "freest opportunity to autonomous development". In response, Emperor Karl I agreed to reconvene the Imperial Parliament in 1917 and allow the creation of a confederation with each national group exercising self-governance. However, the leaders of these national groups rejected the idea; they deeply distrusted Vienna and were now determined to get independence.
On 14 October 1918, Foreign Minister Baron István Burián von Rajecz[4] asked for an armistice based on the Fourteen Points. In an apparent attempt to demonstrate good faith, Emperor Karl issued a proclamation ("Imperial Manifesto of 16 October 1918") two days later which would have significantly altered the structure of the Austrian half of the monarchy. The Polish majority regions of Lesser Poland and part of Galicia were to be granted the option of seceding from the empire to join the earlier established Polish proto-state, in order to reunite with their ethnic brethren in the Polish lands held by Russia and Germany, with the ultimate goal of resurrecting the sovereign Polish statehood. However, the imperial government attempted to curb the Polish ambitions by inciting the Polish-Ukrainian conflict through separating and retaining the remainder of Galicia and the entire Lodomeria, designated in the secret Treaty of Brest-Litovsk (Ukraine–Central Powers) for the purpose of creating a Ukrainian polity, intended in the proclamation to constitute along the rest of Cisleithania a transformed federal union composed of four parts—German, Czech, South Slav and Ukrainian. Each of these was to be governed by a national council that would negotiate the future of the empire with Vienna. Trieste was to receive a special status. No such proclamation could be issued in Hungary, where Hungarian aristocrats still believed they could subdue other nationalities and maintain the "Holy Kingdom of St. Stephen".
It was a dead letter. Four days later, on 18 October, United States Secretary of State Robert Lansing replied that the Allies were now committed to the causes of the Czechs, Slovaks and South Slavs. Therefore, Lansing said, autonomy for the nationalities – the tenth of the Fourteen Points – was no longer enough and Washington could not deal on the basis of the Fourteen Points anymore. In fact, a Czechoslovak provisional government had joined the Allies on 14 October. The South Slavs in both halves of the monarchy had already declared in favor of uniting with Serbia in a large South Slav state by way of the 1917 Corfu Declaration signed by members of the Yugoslav Committee. Indeed, the Croatians had begun disregarding orders from Budapest earlier in October. The Lansing note was, in effect, the death certificate of Austria–Hungary.
The national councils had already begun acting more or less as provisional governments of independent countries. During the Italian battles, the Czechoslovaks and Southern Slavs declared their independence. With defeat in the war imminent after the Italian offensive in the Battle of Vittorio Veneto on 24 October, Czech politicians peacefully took over command in Prague on 28 October (later declared the birthday of Czechoslovakia) and followed up in other major cities in the next few days. On 30 October, the Slovaks followed in Martin. On 29 October, the Slavs in both portions of what remained of Austria–Hungary proclaimed the State of Slovenes, Croats and Serbs. They also declared that their ultimate intention was to unite with Serbia and Montenegro in a large South Slav state. On the same day, the Czechs and Slovaks formally proclaimed the establishment of Czechoslovakia as an independent state.