<prompt> Bhala okuqhubekayo kwalesi sigaba - Ngo-1968, iSoviet Union kanye nabangane bayo beSivumelwano SaseWarsaw bahlasela  <response>: I-Czechoslovakia ukuze imise izinguquko zePrague Spring. Ngemuva kwalokho, uBrezhnev walungisa ukuhlasela kanye nokungenelela kwezempi kwangaphambilini kanye nanoma yikuphi ukungenelela kwezempi okungenzeka esikhathini esizayo ngokwethula iBrezhnev Doctrine, eyayimemezela noma yikuphi ukusongelwa kokubusa kobusoshiyali ezweni leWarsaw Pact njengosongo kuwo wonke amazwe aseWarsaw Pact, ngakho-ke kulunga ukungenelela kwezempi. 