 Complete the following phrase:  As a result of this, by the mid-1970s a systematic emigration of Russians from the republic started, due to the social discirimation in favour of the only nationality all administrative roles of Checheno-Ingushetia by the late 1970s were held by Chechens. By the end of the 1980s, Chechens formed the majority in all mountainous regions, and almost half of the population in traditional ethnic RussianCossack regions left banks of the Terek and Sunzha Rivers, cities of Grozny and Gudermes the catalyst was set for the mass ethnic cleansing of the Russian population that took 