Kazakhstan would be stupid to agree to a Russian plan to send Kazakhstani soldiers to Syria. Under any such plan, the Kazakhstanis would intervene on the Russian side of the conflict. That is, they would be there to prop up the Assad regime and to oppose both ISIS and the various rebel factions supported by Turkey, and the U.S. If they did that, it would completely ruin Kazakhstan's carefully cultivated image as a neutral party to host peace talks. It would also potentially damage relations with Turkey and the U.S., two countries that Kazakhstan has very good relations with.