A Russian military specialist by the name of Igor Shatrov, head of the expert council of the Strategic Development Fund, has stated that Russian troops retreated to protect Donbas, as we read in Crimea.ria:

The regrouping of Russian troops in the areas of Balakleya and Izyum of the Kharkiv region is explained by the need to concentrate forces and strengthen positions in the Donbass, political scientist, head of the expert council of the Strategic Development Fund Igor Shatrov believes.

“No matter how ambiguous it may look from a political point of view, from the point of view of military strategy, a very important point should be noted: I don’t want to offend anyone, but the group in the Kharkiv region carried out the tasks of creating a buffer zone and protecting the Luhansk People’s Republic. … They supported this buffer zone, but a large number of troops were irrationally used in this direction. Therefore, a three-day operation was undertaken to withdraw troops from this direction”

The expert recalled that the main task of the special military operation at the first stage is the liberation of the DPR and LPR. Today, Donetsk needs serious support, so the military command decided to carry out such a regrouping, the analyst suggested.