It appears that the Russian invasion of Ukraine that I have feared since March has now begun in earnest, with the opening of a new front in the vicinity of Mariupol on the shores of the Azov Sea and a major counterattack in Luhansk Oblast leading to the retreat of Ukrainian forces from positions they have occupied (in some cases) since before the June ceasefire. This separatist counteroffensive has generated a lot of discussion among analysts and commentators about whether the forces attacking Novoazovsk and Mariupol belong to regular Russian units or irregular forces, as part of an effort to determine whether or not these new developments amount to a Russian invasion or just a new escalation by separatist forces.

I would argue that the specific provenance of the fighters involved doesn’t actually matter very much in this context. There is no doubt that the forces attacking in the south, near Novoazovsk and Mariupol, came directly from Russia, not from territory already controlled by the separatists farther north. To do so, they had to be allowed through the border by Russian border guards.

Furthermore, there is also no doubt that they are using weapons and equipment supplied by the Russian government, since they are no longer even trying to claim that the equipment they are using was captured from defeated Ukrainian forces.

In these circumstances, why does it matter which specific people are sitting in the tanks?

And if it did matter, there is now more and more evidence being uncovered in Russian social media and in independent reporting that active duty Russian personnel are fighting in Ukraine. This includes the ten Russian soldiers that the Ukrainian government has claimed to have captured on Ukrainian territory, as well as the various Russian soldiers from units such as the 76th Airborne Division based in Pskov who have been reported to have died recently in unexplained circumstances.

One can invade a country through a direct frontal assault. Or one can do it in secret, a little bit at a time. The Russian government has chosen the second path. It doesn’t make it any less of an invasion.

It also means that the Minsk talks are almost certainly a diversion, meant to distract Western leaders from the reality of what is happening on the ground. The idea is that as long as world leaders think there is a chance at successful peace talks, they will refrain from strong words or actions condemning what Russia is doing in Ukraine. This seems to be working out for Russia so far but it should not distract us from events on the ground.

I should be clear that I don’t think Russia is currently planning a full takeover of any part of eastern Ukraine. The goal remains what it has been for months now: to ensure that Ukraine remains unstable and weak. For now, in order to accomplish this goal, Russia needs to make sure the separatists are not defeated and remain a viable force. Both the escalation in assistance and the opening of the new front are a response to the losses that the separatists had suffered in recent weeks.

In the long run, the only acceptable end to the conflict for Russia is one that would either freeze the current situation in place with separatists in control of significant territory in eastern Ukraine (the Transnistria variant) or the removal of the pro-Western Ukrainian government and its replacement by a pro-Russian one. Participants in peace talks have to understand that this is essentially a red line for Moscow. President Vladimir Putin will not allow the restoration of control over eastern Ukraine by the current Ukrainian government by peaceful means and is clearly willing to directly involve Russian forces in military action to ensure that it doesn’t happen through an Ukrainian military victory.

Given Russia’s superior military capabilities this is a war that Ukraine cannot win, at least not by military means. The alternatives are to make a deal with whatever terms are possible or to continue the struggle for a long time, hoping that inflicting a high cost on Russian forces will eventually turn Russians against their government’s adventure. The former will lead to the collapse of the Ukrainian government. The latter will take a very long time at best and result in huge numbers of civilian casualties.

This story first appeared at Russian Military Reform, August 27, 2014.