August 7, 2014
Two months of steady advance by Ukrainian security forces have brought the war in Ukraine’s southeast to a crucial point at which Russian President Vladimir Putin must decide whether to launch a conventional invasion. The next four weeks, before NATO’s annual summit conference, are a critical window for action by Ukraine and its Western allies to forestall such a disastrous new escalation by Russia of its war.

North American and European governments must signal unambiguously to Mr. Putin that they are ready to penalize his economy with broader sanctions and to change NATO’s posture toward Russia if he invades. Ukraine has an opportunity, until the summit on September 4-5, to complete its military defeat, or at least its isolation, of the Russian-sponsored rebels, insofar as it can do so without causing widespread civilian casualties.

Here is why the situation has become critical: Ukrainian troops have pushed Moscow’s proxy forces in southeast Ukraine back to the region’s principal cities, Luhansk and Donetsk, isolating those rebel concentrations from each other. Ukraine is on the verge of closing all supply lines to the separatists in Donetsk. A cut-off of the rebels’ supplies would mean their eventual defeat. (The Kremlin tried to prevent this by giving the rebels heavier weapons, including tanks and the SA-11 missile system that let them shoot down, accidentally, Malaysian Airlines Flight 17.)


Will Putin Invade?
 
Thus Moscow may soon face the hard choice of letting its insurgency fail or invading Ukraine overtly. Moscow has positioned its army for an invasion, massing as many as 20,000 soldiers along the border. It has tried to intimidate Ukraine by conducting military exercises in its Western Military District and sending warplanes into Ukrainian airspace. It even has shelled Ukrainian forces along the border that have interdicted Russia’s supply routes to the rebels.

For weeks, the Russian propaganda machine has been speaking of the growing danger to civilians from Ukraine’s military operation and the need to establish “humanitarian corridors.” This signals that Mr. Putin might clothe an invasion as a “humanitarian operation” to better defend it in the West and reduce the severity of additional sanctions.

So will Mr. Putin invade? He first must place his bet about how forcefully the US and Europe would escalate their sanctions in response. If he is willing to expose his economy to that further penalty, he then must decide when to attack.


NATO Summit May Delay Kremlin

The increasingly difficult straits of Moscow’s clients would argue for prompt action. August, when Europe and Washington are on vacation, is normally a good time to move, as Moscow did in 2008 with its invasion of Georgia.

This year, however, an August invasion would virtually invite NATO to respond at its upcoming summit. The summit’s original agenda featured the withdrawal from Afghanistan and such riveting subjects as the building up of NATO partner capacity. While Moscow’s aggression in Ukraine has seized NATO’s attention, the Alliance response so far has been rather mild: the deployment of a few military assets to the eastern members of the Alliance and a willingness to conduct some exercises there.

An August conventional assault on Ukraine, even under the thin disguise of establishing a humanitarian corridor, would give the NATO hawks strong arguments for a much more robust response.  For Mr. Putin it would be better to wait. 

What the West Must Do

For Ukraine’s President Petro Poroshenko the calculation is the opposite. His forces already are moving forward nearly every day. He has a window of opportunity to finish the job before NATO leaders convene. Opportunity, however, does not come without danger. Moscow’s agents in Ukraine’s East have adopted the Hamas strategy of seeking protection among the civilians in Donetsk and Luhansk. So Mr. Poroshenko faces a dilemma. If he sends his forces into Donetsk and Luhansk to complete the pacification of the East before the summit, he risks major civilian casualties. 

Alternatively, his forces can use the coming weeks to isolate Moscow's proxies in the two cities and prevent their resupply. While this would weaken the separatists, it would be unlikely to lead to their defeat before NATO's summit. The Ukrainian forces also could fortify their positions as they play the longer game, but the game would still be on after the NATO Summit, when Mr. Putin may feel less constrained.

Decisive yet prudent Western statesmanship is needed now to prevent a Russian invasion. The US and European Union must state unequivocally what additional heavy sanctions will hit Russia if Mr. Putin sends in his army. NATO must make clear as well that a  Russian invasion of Ukraine will undermine the NATO-Russia Founding Act and prompt the Alliance to deploy a major component of air and other forces forward to its eastern members. Mr. Putin and his military and economic advisers should understand in advance the high cost of unleashing Russia’s army.

John E. Herbst is director of the Dinu Patriciu Eurasia Center at the Atlantic Council. He served as US ambassador to Ukraine from 2003 to 2006.

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