蘇聯自 1922 年建立後，在主權的實踐上有兩重要的轉折點，一是 1922 年的建立，是透過條約的簽訂而組成。也就是 1922 年的蘇聯在本質上具有「邦聯」的性質。但是，隨著 1924 年蘇聯憲法的通過，「邦聯」的蘇聯轉換 成「聯邦」的蘇聯，原來俄羅斯聯邦、烏克蘭、白俄羅斯及外高加索聯邦四個共和國主權的安排，透過憲法架構下「自由退出權」的設計得到妥協。在這樣的架構下，蘇聯體制的變異性成為一個特殊的現象。這種變異性使蘇聯在聯合國創立之初，就出現「一國三席」的特殊現象:除蘇聯在安理會擔任常任理事國外，蘇聯 15 個加盟共和國中的烏克蘭及白俄羅斯兩個加盟共和國亦成為聯合國會員國，而在大會中擁有席次。

During its establishment in 1922 and political transformation in 1924, the USSR transformed from a confederation to a federation through the Soviet Constitution in 1924. As a result, four sovereignties, including the original Russian SFSR, the Ukrainian SSR, the Byelorussian SSR, and the Transcaucasian SFSR, were entitled free exit rights as a compromise under the constitutional framework. This structure led to a unique phenomenon where one nation had three seats at the UN. While the USSR served as a permanent member in the UN Security Council, the Ukrainian SSR and the Byelorussian SSR, two of the fifteen union republics of the USSR, were also official UN members with seats in the General Assembly.