So Much for Peacekeepers

Latest news from South Ossetia: Georgian forces retreating from Tskhinvali ahead of a column of Russian tanks moving down from the border. Russian military aircraft is bombing Georgian forces, including the Vaziani military base, where American military instructors are located.

We're still in the middle of the three-hour window that the Georgians said they would allow for the evacuation of civilians, so the reports might not even be true; but if they are, it does seem like Russia will no longer have any way of pretending it is not a clear and present threat to Georgia, as opposed to an international peacekeeping observer.

Could be a failure by the Georgian military. Could be the successful result of a planned provocation designed to expose Russia's true role in the events. In any case, it is certainly a smart move on Georgia's part to avoid engaging the Russian army.

The question is, are these volunteers, or actual Russian regular forces; and if the latter, was their deployment a kneejerk reaction by one of the theater commanders, or did it come direct from Putin/Medvedev?

UPDATE: RIA Novosti, the official Kremlin newswire, reports that the Russian Defense Ministry has confirmed that regular army forces have been sent into South Ossetia, ostensibly to relieve the peacekeeping forces (which was not allowed under the terms of the original ceasefire).

UPDATE 2: Latest news say Russian tanks from the 58th Army are now in direct engagement with retreating Georgian forces.
Saw some info on the orders of battle. The South Osettians themselves have a decent quantity of armor, but apart from that they are very definitely the weakest force in the conflict. The Georgian military is considered to be the best-trained and best-armed in the entire former Soviet Union, with American training, some American armor and aircraft, and a lot of state-of-the-art battlefield equipment from Israel and other suppliers; but they are not very big in numbers, only approximately 30 thousand regulars with 100 thousand trained reservists. Russia's North Caucusus Military District is about a hundred thousand regular troops, with more armor and equipment than the Georgians.