Could the Russian Empire have expanded into Kazakhstan earlier? Or was the mid to late 19th century the earliest possible time due to technology and the density of Russian settlement north of the Ural River?
Alternatively, could Russian colonization of Central Asia have been delayed, and Kazakhs remain independent longer?
What, qualitatively, was the turning point? Why did the Russians shift from a defensive strategy to an offensive strategy in Kazakhstan, eventually destroying the Kazakh Khanate in 1847?