Was the Rus Conquest of Kiev from the Khazar Empire the key victory that led to the unification of Russia?

https://www.quora.com/Was-the-Rus-Conquest-of-Kiev-from-the-Khazar-Empire-the-key-victory-that-led-to-the-unification-of-Russia

 

There is no evidence that Kyiv was the part of Khazar Empire. We only know that Kyiv land was populated by East Slavic tribe, that paid tribute to Khazars. Kyivans were temporary vassals of Khazar Empire, but not the part of it. There is no evidence that Kyivan fortress was built by Khazars or that there was Khazar garrison in the city. We only know that Khazars had their own name for Kyiv - Sambatas. Nevertheless there were ruined Slavic fortifications on the place where that new fortress has been built, so Kyiv originally was Slavic city. If Kyiv really was the part of Khazar Empire, than Khazars would send troops to recapture the city - and we know nothing about such raid. There is no evidence that there were any Khazars in Kyiv during and after capturing Kyiv by Rus'. It would have been mentioned in the chronicle.