A return to war in Ukraine? Kiev, rebels trade accusations of buildup.

Both Ukraine's government and its rebel provinces have rebuilt their militaries, raising the stakes should the latest violence turn into all out combat.

Fighting in eastern Ukraine throughout the summer has provided a daily litany of ceasefire violations. But the latest surge in fighting has moved beyond that. Now it appears that both sides are accusing the other of preparing to break out of the collapsing Minsk-II peace accord by launching a full-scale offensive.

And whether either or both sides are preparing to restart the conflict, it is a fight that neither Russia nor the West want to see.

The only part of the Minsk agreement that has worked to any degree is its imposition of a ceasefire and a pullback of heavy weapons from the line of contact, and even that appears to be unraveling. The deal's political prescriptions, which called for the gradual reintegration of the rebel statelets of Donetsk and Luhansk into Ukraine through local elections, along with gradual restoration of economic links, and the return of border control to Kiev by year's end, have failed to make it out of the starting gate.

Now, mutual recriminations between Kiev and Moscow are intensifying, as a decision whether or not to renew sanctions comes at the end of the year. 

The US and European Union have made clear they will lift anti-Russia sanctions only if Minsk is "fully implemented." Moscow and Kiev continue to accuse each other of willfully sabotaging the deal.

"It's now one hundred percent clear that Minsk will not be implemented, and peoples' minds are turning to what happens when that becomes officially clear on Dec. 31," says Sergei Strokan, foreign affairs columnist with the liberal Moscow daily Kommersant. "Will the West ramp up sanctions, double down on attempts to isolate Russia, and deepen the cold war atmosphere? Or will there be a return to the bargaining table, maybe some kind of Minsk-III, that addresses all the flaws of the previous one? We do not know, and there seems to be no big appetite in Russia or the West for either of those paths."

Rebuilt and rearmed

Another possibility, increasingly mentioned amid the growing turmoil in eastern Ukraine, is a return to the battlefield by rebels or Kiev, in a bid to reset the options.

In the past year Ukrainian rebels, with Russian help, have built up their forces from a gaggle of ragtag irregulars to what even Kiev admits is probably now a modern, disciplined army of 40,000, suitable for a "midsized European state."

Ukraine's own army has been greatly strengthened through six waves of military "mobilization." It has received limited arms deliveries and significant training from the US, Canada and other Western nations, and could now be ready for a full assault on the rebel strongholds despite reports of widespread draft dodging, desertion, and public apathy.

On Monday, Russian Foreign Minister Sergey Lavrov alleged that Kiev is preparing for a final showdown. He said the current situation is like a year ago, when Ukrainian forces were decisively defeated by rebels – almost certainly backed by regular Russian forces – as they attempted to encircle the rebel capital of Donetsk.

"[In August 2014] Ukrainian military was commanded to advance, but the offensive died out and they Kiev agreed to negotiate. That was Minsk-I," Mr. Lavrov said, implying that any fresh offensive by Ukraine would meet a similar fate.

For its part, Kiev accuses Russia of massing 50,000 troops on its border in a bid to pressure Ukraine. In a Facebook posting, Ukrainian President Petro Poroshenko slammed Vladimir Putin for visiting Crimea on Monday, which Mr. Putin said was to "promote tourism."

Mr. Poroshenko also warned that Russian backing for east Ukraine rebels is "a challenge to the civilized world and the continuation of the scenario to fuel tensions."

'Not ready for genuine compromise'

Mr. Strokan suggests the moods in Kiev and Moscow mirror each other, and both believe time is on their side. In Kiev there is a feeling that, with the West behind them and sanctions hammering Russia's economy, Putin's days must be numbered. In Moscow there is a sense, bolstered by daily media stories of economic doom in Ukraine, that the Kiev government cannot survive for much longer.

"There's a certain amount of truth in both views, actually. Neither side can really afford a return to full-scale war right now. So they talk war instead," he says.

"But the basic problem remains. Minsk is not working, the clock is ticking, and neither side is prepared for genuine compromise. What is it going to be? Without a strong new diplomatic effort backed by the West and Russia to impose a political settlement, I'm afraid more war looks like the default setting."