In late 1920, Armenia was invaded by Kemalist Turkey, ending with its partition and sovietisation by the Russian SFSR, with the latter founding the superseding Armenian Soviet Socialist Republic.

In the two and a half years of its existence, Armenia formed diplomatic relations with 40 countries, gained de jure recognition, underwent parliamentary elections, and founded its first university.

According to historians Edmund Herzig and Marina Kurkchiyan, "in the late eighteenth and through the nineteenth centuries a coherent sense of Armenians as a nation with a distinct and distinguished history was spread by patriots, teachers, writers, and revolutionaries".

[23] The Russian offensive during the Caucasus campaign of World War I, the subsequent occupation and creation of a provisional administrative government gave hope for ending Ottoman Turkish rule in Western Armenia.

[32] Without awaiting the TDFR's consent to the new terms, the Ottomans resumed their offensive in Armenia on 21 May, leading to the battles of Abaran, Karakilisa, and Sardarabad, whereby local Armenian forces emerged victorious.

Hovannisian estimates that at least 8,000 young men were taken to Erzurum for slave labour, and 125,000 livestock, 30,000 agricultural equipment, 6,000 carts and 18,000 tons of foodstuffs were confiscated by the retreating Ottoman army.

[54] Armenia was unsuccessful in its objective of occupying lands up to the Khrami river[55] and was pushed back by Georgian forces to the village of Sadakhlo by the time of the ceasefire which came into effect at midnight on 31 December.

[72] The Ninth Army of the Ottoman Empire occupied the Kars Oblast at the time of the Armistice of Mudros, being permitted to winter in the district until early 1919; on 7 January 1919, the British ordered their complete withdrawal to the pre-war Russo-Ottoman border.

[76] Consequently, the Kars Oblast (excluding western Olti and northern Ardahan)[77] was annexed to Armenia, falling under the civil governorship of Stepan Ghorghanyan [hy][78]—this allowed for the repatriation of 60,000 Armenians[79] (out of more than 100,000 had fled in April 1918).

[84] British sympathy to the Aras Republic was reversed under the authority of Major-General William Montgomerie Thomson who suspected Pan-Turkic influence in Nakhchivan due to the presence of Azerbaijani and Ottoman envoys.

On 13 May 1919, Khatisian arrived in Nakhchivan to discuss terms of capitulation with the minister of war of the Aras Republic, Kalb Ali Khan Nakhichevanskii [ru], thereby effecting the annexation.

[87] Beginning in July 1919, a series of insurgencies against Armenian rule erupted in the Kars and Nakhchivan regions, fostered by Azerbaijani[88] and Turkish envoys who instructed local Muslims to resist.

According to Hovannisian, a population exchange whilst practical was deemed "preposterous" for the Karabakh Armenians because the region's cession "to the Pan-Turanian fanatics will open the door to endless invasions, endanger the peace of the Orient, and shake the political equilibrium off its foundations".

[98] Nagorno-Karabakh, despite initially being self-governed, capitulated to British–Azerbaijani pressure and became an autonomous part of Azerbaijan through an agreement signed on 22 August 1919,[99] pending the Paris Peace Conference's decision on the inter-Caucasian borders.

[101] Andranik, who had been tasked with the defence of Erzurum,[102] denounced the Dashnaks and Armenia for their treachery in seeking peace after gaining the upper hand in battle, seeing them as becoming "nothing more than an Ottoman vassal state".

[98] In early November 1919, Azerbaijan launched a campaign to incorporate the region and absorb Muslim-controlled Nakhchivan, however, were forced to retreat some days later due to their defeat in battle, despite initially meeting success on all fronts.

[155] As no country was willing to assume the mandate over Armenia, the peace conference decided to only assign it the vilayets of Erzurum, Van, Bitlis, and Trebizond,[156] with the precise boundary to be arbitrated by American president Woodrow Wilson.

[165] Armenia, in reaction to the "furor" among Allied circles caused by the treaty, stated that "In view of the extraordinary pressure exerted from all sides and the fact that the Armenian army was alone and heavily outnumbered, the government had accepted the temporary arrangement in order to win some time.

Henceforth, Soviet Armenia's Red Flag will protect the working people from the centuries-long yoke of the oppressors[190]According to Hovannisian, the declaration "emphasized the beginning of a new era in relations with Azerbaijan and Turkey ...

On 30 November, Azerbaijani revolutionary Nariman Narimanov issued a decree stating that "Mountainous Karabagh, Zangezur, and Nakhichevan have to be considered a part of the Armenian Socialist Republic"—this cession was done "because boundaries had no meaning among the family of Soviet peoples".

Vratsian made appeals to the West and Turkey, calling the latter to honour its commitment in the Treaty of Alexandropol to come to Armenia's aid, however, all were unanswered; after conquering Georgia, the Red army turned its attention to the revolt.

[194] Alexander Miasnikian, the head of the Armenian Revkom offered amnesty and assurances regarding the retention of Zangezur to Mountainous Armenia—on 16 July 1921, the rebels folded, retreating over the Aras river into Iran.

[209] The party also suffered from "contradictions between nationalism and socialism" and "a widening rift between intellectuals and partisan chief"—despite these factors, the Dashnaks placed "great importance on showing a solid front".

The Armenian Populist Party, formed in 1917 from the Russian Kadets were "purely bourgeois and antirevolutionary",[211] and shared the posts of the second cabinet with the Dashnaks and "advanced a program of liberal, evolutionary reforms and drew its adherents primarily from among the professional-commercial classes of Tiflis and Baku".

However, following the events of World War I, Eastern Armenian Hunchaks became Mensheviks or Bolsheviks—by this time, the party in the Caucasus was held together by a "small circle of old loyalists and a few refugee members from Van".

Before the Russian Revolution, the SRs "decried the chauvinism and racial strife" and called for a united front against the autocracy of the Tsar—despite their appeals, they "scarcely made a ripple in the Armenian provinces".

According to Hovannisian, "the union's executive was instructed to stress the working-class nature of the movement by excluding rich peasants (kulaks) and developing facets of the rural economy which benefited the toilers".

The Hai-Koop, which came as an "amalgamation" of consumer cooperative groups, strove to serve as "local agencies of production and distribution, as intermediaries between the government and primary producers, and as mainstays of communal self-improvement and popular democracy".

[235] In May 1919, the government adopted a plan to establish the country's first university with faculties of history and philology, law, medicine, and physical sciences—it was opened on 31 January 1920 and classes began on 1 February with 8 professors and 200 students.

The minister of education and culture, Nikol Aghbalian, declared that "with the opening of the historico-philological branch of the state university, Armenia was taking a major step toward restoring the old, traditional bonds with the great civilizations of the West".