In April 1918, the British Cabinet, in the face of the crisis caused by the German Spring Offensive, attempted with a dual policy to simultaneously link the enactment of conscription into Ireland with the implementation of Home Rule, as outlined in the report of the Irish Convention of 8 April 1918.
The Union of Bessarabia with Romania was signed on 9 April 1918. The unification act that brought these lands within the modern Romanian state was not recognized by Bolshevik Soviet Russia, but it was occupied with fighting the White movement, Poland and the Ukraine in its war for independence, and resources were not available to challenge Romania.
Romania was alone on the Eastern Front, a situation that far surpassed its military capabilities. Therefore, on 7 May 1918, Romania sued for peace. The prime minister of Romania, Alexandru Marghiloman, signed the Treaty of Bucharest (1918) with the Central Powers. However, this treaty was never signed by King Ferdinand of Romania.
Stravinsky struggled financially during this period. Russia (and its successor, the USSR) did not adhere to the Berne Convention and this created problems for Stravinsky when collecting royalties for the performances of all his Ballets Russes compositions. Stravinsky blamed Diaghilev for his financial troubles, accusing him of failing to live up to the terms of a contract they had signed. He approached the Swiss philanthropist Werner Reinhart for financial assistance while he was writing L'Histoire du soldat (The Soldier's Tale). Reinhart sponsored and largely underwrote its first performance, conducted by Ernest Ansermet on 28 September 1918 at the Théâtre Municipal de Lausanne. In gratitude, Stravinsky dedicated the work to Reinhart and gave him the original manuscript.
On 31 October 1918, the Aster Revolution in Budapest brought Hungarian liberal aristocrat Mihály Károlyi, a supporter of the Allied Powers, to power. The Hungarian Royal Honvéd army still had more than 1.400.000 soldiers when Mihály Károlyi was announced as prime minister of Hungary. Károlyi yielded to U.S. President Woodrow Wilson's demand for pacifism by ordering the disarmament of the Hungarian army. This happened under the direction of Béla Linder, minister of war in the Károlyi government. Due to the full disarmament of its army, Hungary remained without a national defence at a time of particular vulnerability.
On the night of 2–3 November 1918 and with the aid of Ahmed Izzet Pasha, the Three Pashas (which include Mehmet Talaat Pasha and Ismail Enver Pasha, the main perpetrators of the Genocide) fled the Ottoman Empire.
On 10 November 1918, taking advantage of the Central Powers' precarious situation, Romania re-entered the war on the side of the Allied forces, with similar objectives to those of 1916. King Ferdinand called for the mobilization of the Romanian army and ordered it to attack by crossing the Carpathian Mountains into Transylvania. The end of World War I that soon followed did not bring an end to fighting for the Romanian army. Its action continued into 1918 and 1919 in the Hungarian–Romanian war.
In other action during the Meuse-Argonne Offensive, Truman's battery provided support for George S. Patton's tank brigade, and fired some of the last shots of the war on November 11, 1918. Battery D did not lose any men while under Truman's command in France.
On 13 November, Károlyi signed an armistice with the Allied nations in Belgrade. It limited the size of the Hungarian army to six infantry and two cavalry divisions. Demarcation lines defining the territory to remain under Hungarian control were made.
Following the 1918 Treaty of Bucharest, the bulk of the Romanian Army was demobilized. Only the 9th and 10th infantry divisions and the 1st and 2nd cavalry divisions were at full strength. However, those units were engaged in the protection of Bessarabia against the Bolshevik Soviet Russians. The 1st, 7th and 8th Vânători divisions, stationed in Moldavia, were the first units to be mobilized. The 8th was sent to Bukovina and the other two were sent to Transylvania. On 13 November, the 7th entered Transylvania at the Prisăcani River in the eastern Carpathians. The 1st then entered Transylvania at Palanca, Bacău.
The lines would apply until definitive borders could be established. Under the terms of the armistice, Serbian and French troops advanced from the south, taking control of the Banat and Croatia. Czechoslovakia took control of Upper Hungary and Carpathian Ruthenia. Romanian forces were permitted to advance to the River Maros (Mureș) . However, on 14 November, Serbia occupied Pécs.
Stresemann then gathered the main body of the old National Liberal Party—including most of its center and right factions—into the German People's Party, with himself as chairman. Most of its support came from the middle class and upper-class Protestants.
On 1 December, the Union of Transylvania with Romania was officiated by the elected representatives of the Romanian people of Transylvania, who proclaimed a union with Romania. Later the Transylvanian Saxons and Banat Swabians also supported the union.
Lt. Hasan Maruf of the Ottoman army describes how a population of a village were taken all together and then burned. The Commander of the Third Army Vehib's 12-page affidavit, which was dated 5 December 1918, was presented in the Trebizond (Trabzon) trial series (29 March 1919) included in the Key Indictment, reporting such a mass burning of the population of an entire village near Muş: "The shortest method for disposing of the women and children concentrated in the various camps was to burn them".
The discovery of Planck's constant enabled him to define a new universal set of physical units (such as the Planck length and the Planck mass), all based on fundamental physical constants upon which much of quantum theory is based. In recognition of Planck's fundamental contribution to a new branch of physics, he was awarded the Nobel Prize in Physics for 1918 (he actually received the award in 1919).
Trabzon was the main city in Trabzon province; Oscar S. Heizer, the American consul at Trabzon, reported: "This plan did not suit Nail Bey ... Many of the children were loaded into boats and taken out to sea and thrown overboard". Hafiz Mehmet, a Turkish deputy serving Trabzon, testified during a 21 December 1918 parliamentary session of the Chamber of Deputies that "the district's governor loaded the Armenians into barges and had them thrown overboard".