In the final years of World War I, Nakhichevan was the scene of bloodshed between Armenians and Azerbaijanis, who both laid claim to the area.

When the TDFR was dissolved in May 1918, Nakhichevan, Nagorno-Karabakh, Zangezur (today the Armenian province of Syunik and part of the province of Vayots Dzor), and Qazakh were heavily contested between the newly formed and short-lived states of the Democratic Republic of Armenia (DRA) and the Azerbaijan Democratic Republic (ADR).

[4] Under the terms of the Armistice of Mudros, the Ottomans agreed to pull their troops out of the Transcaucasus to make way for the forthcoming British military presence.

[6] In December 1918, with the support of Azerbaijan's Musavat Party, Jafargulu Khan Nakhichevanski declared the Republic of Aras in the Nakhichevan uyezd of the former Erivan Governorate assigned to Armenia by Wardrop.

Bechhofer described the situation in April 1920: You cannot persuade a party of frenzied nationalists that two blacks do not make a white; consequently, no day went by without a catalogue of complaints from both sides, Armenians and Tartars [Azeris], of unprovoked attacks, murders, village burnings and the like.

The fall of the Aras republic triggered an invasion by the regular Azerbaijani army and by the end of July, Armenian troops were forced to leave Nakhichevan City to the Azeris.

According to the formal figures of this referendum, held at the beginning of 1921, 90% of Nakhichevan's population wanted to be included in the Azerbaijan SSR "with the rights of an autonomous republic.

"[10] The decision to make Nakhichevan a part of modern-day Azerbaijan was cemented 16 March 1921 in the Treaty of Moscow between Bolshevist Russia and Turkey.

[3] As a constituent part of the Soviet Union, tensions lessened over the ethnic composition of Nakhichevan or any territorial claims regarding it.

[3] It also served as an important strategic area during the Cold War, sharing borders with both Turkey (a NATO member state) and Iran (a close ally of the West until the Iranian Revolution of 1979).

At any one time, between 70% and 85% of Nakhichevan's population was infected with malaria, and in the region of Norashen (present-day Sharur) almost 100% were struck with the disease.

[19] Heydar Aliyev, the future president of Azerbaijan, returned to his birthplace of Nakhichevan in autumn 1990, after being ousted from his position in the Politburo by Mikhail Gorbachev in 1987.

In 2008, the National Bank of Azerbaijan minted a pair of gold and silver commemorative coins for the 85th anniversary of the creation of the Nakhichevan Autonomous Soviet Socialist Republic.

[21] 1918–24  Turkestan3 1918–41  Volga German4 1919–90  Bashkir 1920–25  Kirghiz2 1920–90  Tatar 1921–91  Adjarian 1921–45  Crimean 1921–91  Dagestan 1921–24  Mountain 1921–90  Nakhichevan 1922–91  Yakut 1923–90  Buryat1 1923–40  Karelian 1924–40  Moldavian 1924–29  Tajik 1925–92  Chuvash5 1925–36  Kazakh2 1926–36  Kirghiz 1931–92  Abkhaz 1932–92  Karakalpak 1934–90  Mordovian 1934–90  Udmurt6 1935–43  Kalmyk 1936–44  Checheno-Ingush 1936–44  Kabardino-Balkarian 1936–90  Komi 1936–90  Mari 1936–90  North Ossetian 1944–57  Kabardin 1956–91  Karelian 1957–92  Checheno-Ingush 1957–91  Kabardino-Balkarian 1958–90  Kalmyk 1961–92  Tuvan 1990–91  Gorno-Altai 1991–92  Crimean