I-USSR imele I-Union of Soviet Socialist Republics, yize yaziwa nangokuthi yiCCCP (isifinyezo esifanayo ngesiRashiya) noma iSoviet Union. Kwakuwumbuso wobumbano osuselwe kubusoshiyali beMarxist (owokuqala emhlabeni) owasungulwa ngo-1922 futhi wahlakazeka ngokuphelele ngo-1991 ngenxa yezinkinga eziningi zezomnotho nezepolitiki ezazisikhathaze kusukela ngawo-80.
Umsuka wawo ukuRevolution yaseRussia (1917), okwakuyi- ukuwa kombuso wama-tsarist. Lokhu kwaholela kuHulumeni Wesikhashana owasuswa ngokushesha wafakwa omunye wemibono yamakhomanisi. Ngokushesha i-USSR yayizozalwa noma, njengoba izakhamuzi zayo zayibiza kanjalo, i-Union (iSoyuz ngesiRashiya).
Phakathi kuka-1940 no-1991, i-USSR yahlukaniswa yaba ngama-republic ayi-15: I-Armenia, i-Azerbaijan, iBelarus, i-Estonia, iGeorgia, iKazakhstan, iKyrgyzstan, iLatvia, iLithuania, iMoldova, iRussia, iTajikistan, iTurkmenistan, i-Ukraine ne-Uzbekistan. Ngokubambisana bakha inyunyana, yize empeleni babenamandla amancane. Lokhu kwawela cishe ngokuphelele kuhulumeni omkhulu, oseRussia Federal Soviet Republic (RSFSR).
I-USSR yayilawulwa yiQembu lamaKhomanisi kuwo wonke amazinga, unobhala walo jikelele kungumholi onamandla kunabo bonke ezweni. Imboni yaseSoviet yayingaphansi kukahulumeni, ophinde wayiphatha. Ngale njongo, wathatha umhlaba wezolimo wawahlukanisa waba amapulazi ombuso, amapulazi ahlanganyelwe (aziwa njenge-sovjoses nama-kolkhozes, ngokulandelana), neziza ezincane ezizimele.
Ngaphezu kukahulumeni kanye nomnotho wayo osezingeni eliphezulu, esinye isici se-USSR ukucindezelwa kwayo kwezepolitiki, yize kwavela kanjalo omunye wemibuso emibili kuphela enamandla omhlaba ngemuva kweMpi Yezwe II. Enye kwakuyi-United States.