Third War of Arab Unification
The Third War of Arab Unification (Arabic: الحرب الثالث للتوحيد العربي al-ḥarb ath-thālith lit-tawḥīd al-‘arabī) was a major armed conflict eventually involving all states of the Arab world and many other surrounding and allied/opposing states, which lasted from 11 February 1986 to 20 October 1989. The third major iteration of the Wars of Arab Unification which have been ongoing at various levels of intensity since 1948, the climax of this war led to the Arab Union's completion of its campaign to unite the entire Arab world, and its political reorganisation from a unitary to a federal presidential republic, which was officially encoded in the 1990 Constitution of the Arab Union.
A direct result of the Arab Nationalist Front (ANF)'s insurrection of 11 February 1986 against the then-unitary iteration of the Arab Union (the United Arab Republic), it resulted in a three-and-a-half-year long war in which a the ANF and its supporters (such as the Muslim Brotherhood and Zionist Resistance Front) sought to prevent the Arab Union from growing through the addition of more republics (at the time, the Arab Union consisting only of Egypt, Libya, Palestine, Lebanon, Syria, Iraq and the Peninsular Republic, the latter formerly a monarchy known as Saudi Arabia), with the Union Defence Forces of the Arab Union seeking to maintain the existing union (which entails both external and internal battles) and ultimately adopt the remaining sovereign Arab states into the union.
Ultimately, following the defeat of the ANF and supporting anti-unionist forces by the Arab Army and the wider Union Defence Forces of which it is part in mid-October 1989, all 13 of the remaining Arab states joined the Arab Union, with the war officially ending on 20 October. Less than a year later, the 1990 Arab Union Constitution was officially approved by the Arab Congress and signed by President Hafez al-Assad on 20 February 1990, which converted the Arab Union from a unitary state officially called the "United Arab Republic" to a federation officially called the "Union of Arab Republics". Under the new constitution, the central government would become the federal government of the Union and each of the 20 federated states (officially known as republics and their sub-federal governments as governorates), with each republic's territory corresponding to that during its sovereignty prior to entering the Arab Union.
The finale of the long-time Wars of Unification ultimately resulted in the historical establishment of the Arab Union as a sovereign federation, the subsequent political and economic integration of the Arab world and its self-realisation as a united state on the global stage as a major power, representing a major geopolitical change with world-shaking consequences.