Complex sentence: The Tsarist government was not ready to colonise the area and was in no position to prevent the Oirats from encamping in the region, but it had a direct political interest in ensuring that the Oirats would not become allied with their Turkic-speaking neighbours.
Split into simpler sentences: The Tsarist government was not ready to colonise the area and was in no position to prevent the Oirats from encamping in the region. But it had a direct political interest in ensuring that the Oirats would not become allied with its Turkic-speaking neighbours.