Russia's long shot in the Donbas

On the other hand, it’s difficult to believe in the success of the larger plan to surround the Ukrainian grouping in Donbas, even with full deployment of available reserves. The frontline that stretches from Staryi Saltiv near Kharkiv to Kamianske near Zaporizhzhia is close to 600 kilometers (approximately 400 miles) in length. If the Russian forces succeed in surrounding the Ukrainian fighters (and they would have to advance by about 120 kilometers, or roughly 75 miles, in order to accomplish this), the two encirclement fronts — the internal and the external one — would add more than 200 kilometers, or over 125 miles, to the frontline’s total length.

According to the theory taught in Russian military schools, a motorized infantry battalion’s offensive strip should not comprise more than two kilometers, or just over a mile (assuming that there is direct contact with neighbors on the flanks). It follows that an operation on the scale just discussed would require at least 400 such battalions. Meanwhile, each Russian battalion tactical group (the battalion with its support units: communications, electronics, and artillery) consists of 700–900 servicemen. In other words, a successful offensive in the Donbas alone would require at least 300,000 Russian soldiers.

Meanwhile, experts estimate that no more than 70–80 battalion tactical groups — that is, no more than 60,000 Russian servicemen — are operational in all of Ukraine. In early March, the overall grouping numbered no more than 100,000 combatants, albeit without considering the additional forces of the LNR, DNR, and Russia’s National Guard.