France, in particular, was keen on the participation of Romania in the intervention against the Bolshevik forces in Russia while the Romanian authorities conditioned this involvement on the fulfillment of the promises made by the Allies in 1916.

However, Romania's motivations to enter the neutral zone and cross the demarcation lines were not limited only to protecting the ethnic Romanians, but also to occupy the territory in accordance with the 1916 agreement, thus presenting the Allies with a fait accompli.

Moreover, the decision of the Council of Four to establish a neutral zone that largely reflected the treaty between Romania and the Allies in 1916 contributed to the liberal president Count Mihály Károlyi's resignation and the subsequent creation of the Hungarian Soviet Republic.

Károlyi yielded to US President Woodrow Wilson's demand for pacifism by ordering the disarmament of the Hungarian Army, which happened under the direction of War Minister Béla Linder on 2 November 1918.

[citation needed] During the rule of Károlyi's pacifist cabinet, Hungary lost control of approximately 75% of its former prewar territories (325,411 km2 (125,642 sq mi) .

[14] Proclamation of King Ferdinand I of Romania to the Romanian People, 28 August 1916: "In our moral energy and our valour lie the means of giving him back his birthright of a great and free Rumania from the Tisza to the Black Sea, and to prosper in peace in accordance with our customs and our hopes and dreams.

Following a request from Romania, the Allied Command in the east, led by French General Louis Franchet d'Espèrey, allowed the Romanian Army to advance to the line of the western Carpathians.

[36] The communist had real popular support only among the proletarian masses of large industrial centres, especially in Budapest, where the working class represented a high proportion of the population.

On 4 April, South African General Jan Smuts was sent to Hungary and discussed with the Hungarian communist government a proposition that they abide by the conditions previously presented to Károlyi in the Vix Note.

Rather than following the instructions of the Vix Note, the Romanian Army pressed on for the Tisza River, an easily defended natural military obstacle.

Kun was prepared to recognise all of Romania's territorial demands, request the cessation of hostilities and ask for ongoing control of Hungarian internal affairs.

Kun ordered the preparation of an offensive against Czechoslovakia, which would increase his domestic support by making good on his promise to "restore" Hungary's borders.

[43] In June, the Hungarian Red Army invaded the eastern part of the newly forming Czechoslovakia: Slovakia and Carpathian Ruthenia (approximately the former Upper Hungary).

On 3 June, the Romanian Army was forced into further retreat but extended its line of defence along the Tisza River and reinforced its position with the 8th Division, which had been moving forward from Bukovina since 22 May.

Despite promises for the restoration of the former borders of Hungary, after the military successes the communists immediately declared the establishment of the Slovak Soviet Republic in Prešov (Eperjes) on 16 June 1919.

It brought these lands within the modern Romanian state was not recognised by Soviet Russia, which was however, occupied in fighting the White movement, Poland, and Ukraine in its war for independence and so resources were not available to challenge Romania.

The Bolshevik Soviet Russians might have used the Ukrainian paramilitary leader Nykyfor Hryhoriv to challenge Romania, but circumstances for that plan did not prove to be favourable.

Although a Romanian army division and some other newly formed units were moved from the Hungarian front to Bessarabia, those threats did not deter Romania's actions in Hungary.

Three French and two Greek army divisions under General Philippe Henri Joseph d'Anselme with support from Polish, Ukrainian, and Russian volunteers, attacked Soviet troops near Odessa.

Under the command of Vladimir Antonov-Ovseyenko, Bolshevik Soviet Russian troops gathered along the Dniester River in preparation for a large attack on Bessarabia on 10 May.

On 11 July, the council ordered Marshal Ferdinand Foch to prepare a co-ordinated attack against Hungary by using Serb, French and Romanian forces.

On 20 July, Hungarian forces established a solid bridgehead on the east bank of the Tisza at Szolnok, opposed by the Romanian 91st Regiment of the 18th Infantry Division.

On 22 July, Hungarian forces crossed the Tisza River 20 kilometres (12 mi) north of Szolnok and took Kunhegyes from the Romanian 18th Vânători Regiment.

The counter-revolutionary White House Fraternal Association attempted to install Archduke Joseph August of Austria as Hungary's head of state and István Friedrich as prime minister.

[51] Horthy's supporters also included members of the White Guards, who had persecuted Bolsheviks and Hungarian Jews, whom they perceived as communists because of their disproportionate participation in Kun's government.[29]: p.

The council pressured Romania to accept the supervision of an Inter-Allied Military Mission to oversee the disarmament of the Hungarian Army and to see the Romanian troops withdraw.[52]: p.

xxviii [29]: p. 614 The Inter-Allied Military Mission committee included General Harry Hill Bandholtz, who wrote a detailed diary of the events[52] Reginald Gorton; Jean César Graziani and Ernesto Mombelli.[52]: p.

32  Lieutenant Colonel Guido Romanelli, Mombelli's secretary and former military representative of the Supreme Council in Budapest, was accused of being biased against Romania and was replaced.[29]: p.

615  The Inter-Allied Military Mission requested for Romania return to Hungary the largely Hungarian-populated territory between the Tisza River and the first line of demarcation.

They took with them resources including foodstuffs, mineral ores and transportation and factory equipment[58] and also discovered historic bells of Romanian churches in Budapest taken by the Hungarians from the Austro-Hungarian Army, which had not been melted.