War flares in Ukraine. Who's lighting the fuse?

Four months ago, the signing of a cease-fire put a halt to all-out fighting in eastern Ukraine. While fighting never completely stopped, the cease-fire eased it sufficiently that major powers who backed it could turn their attention to other global problems, such as an Iranian nuclear deal.

But today, Ukrainian President Petro Poroshenko told his parliament that Ukraine is facing the "colossal threat" of an imminent, all-out Russian invasion.

So, are the Russians coming? Not quite. While the threat of a return to war is very real, thanks to spiking violence in eastern Ukraine, the instigators look more likely to be Kiev and the rebels, not Moscow or the West.

Experts say that both sides in Ukraine's thawing civil war feel they have lost the attention of their war-weary foreign supporters. In which case, a return to open combat could be the best way to achieve their goals – and avoid hard political and economic realities both sides would prefer to ignore.

War weary

"Ukraine's military needs to get ready for a new enemy offensive, as well as a full-scale invasion along the entire border with Russia," Poroshenko told Ukraine's parliament in his annual state-of-the-nation address. He said there are at least 9,000 Russian troops already in Ukraine, and growing indications that Russia's regular forces are massing on the frontier.

Kremlin spokesman Dmitry Peskov denied that, and suggested Poroshenko is trying to influence the upcoming meeting of the Group of Seven summit this weekend, as well as an upcoming European Union meeting that will discuss renewing sanctions against Russia. "We have often seen Kiev heating up tensions amid big international events, and that appears to be the case here," he said.

It's a rhetorical duel that has played out many times, especially since Poroshenko took power last year, precipitating an escalation in fighting in the east. 

But there is also a sense that the big powers who sponsored the accord, primarily Russia, Germany, France, and the US, are growing weary of the conflict. As a result, they may have agreed among themselves that it should be "frozen" for the time being.

No more Novorossiya?

Nonetheless, fighting is spiking in devastated eastern Ukraine to levels not seen since the adoption of the ceasefire, known as Minsk-II. Pitched battles are said to be underway around the government-held town of Maryinka near the rebel capital of Donetsk, with international monitors on the ground reporting that both sides are bringing their heavy weaponry back to the front line – in defiance of the ceasefire terms.

"The pressure for renewing the war is coming from Kiev and the rebel republics of Donetsk and Luhansk, and not from external sources," says Sergei Strokan, foreign affairs correspondent with the pro-business Moscow daily Kommersant. "Both sides are hostages to the situation, and deeply dependent on outside powers for support. Both feel their sponsors are prodding them in directions they don't want to go. One card they can always play is to intensify the fighting, which will bring the world's attention back to them and further polarize relations between Moscow and the West."

The rebels feel that the Kremlin has abandoned its support for Novorossiya, a hypothetical enlarged pro-Russian Ukrainian state that would encompass all of the Russian-speaking south and east of Ukraine.

The word "Novorossiya" has indeed dropped from the vocabularies of top Russian officials. Oleg Tsaryov, speaker of the self-styled "parliament of Novorossiya," declared it on hold last month because Moscow now views the idea as a violation of the Minsk agreement, which envisages negotiations between the rebels and Kiev to restore an integral Ukrainian state.

"The rebels know that the Kremlin can't afford to ignore them if full-scale war erupts again. Instead of being a frozen conflict, forgotten by the world, it will suddenly become hot and urgent again," says Mr. Strokan. "The Russian public would not accept the rebels being sold out. So everything, including Novorossiya, might be back on the table."

The pain of corruption and reform

For Kiev, renewed warfare offers a way to change the subject from Ukraine's collapsing economy and faltering reforms. Opinion polls show declining faith in leading politicians; almost 60 percent of Ukrainians disapproved of Poroshenko's performance in a March survey.

Prime Minister Arseniy Yatsenyuk fares even worse in the polls, with nearly 70 percent disapproval. "Yatsenyuk has lost even more support that Poroshenko, because the population associates him with economic crisis, unemployment, low salaries, and skyrocketing cost of living," says Anton Grushetsky, an expert with the Kiev International Institute of Sociology, Ukraine's leading public opinion agency.

Experts say even a limited upsurge in the war could quell growing domestic criticism, end any discussion in Europe of relieving sanctions on Russia, and perhaps strengthen Western resolve to provide financial and even military aid to Ukraine.

"Poroshenko has every reason to switch the conversation from economic reforms and the struggle against corruption," says Vadim Karasyov, director of the independent Institute of Global Strategies in Kiev. "As long as he is seen as the main one standing up to Russian aggression in the east, he can dodge a lot of criticism about other things."