Violence is spiking in Ukraine's disputed Donbass region, as heavy fighting between separatist rebels and Kiev forces threatens to ignite all-out war. And as is usual when violence spikes in the disputed Donbass, each side blames the other for breaking the two-year-old cease-fire.

But this time, experts in Moscow, Kiev, and the de facto rebel capital of Donetsk all agree where the underlying cause of the renewed fighting lies: in Washington.

As Donald Trump takes the reins in the US, his administration and some European governments appear to be reconsidering the economic sanctions imposed on Russia over the almost three-year-old conflict. And that threatens to create Mr. Trump's first urgent foreign policy crisis, as each side argues the other is exploiting this uncertain moment to return to the battlefield hoping to grab quick advantages.

Reaction to Trump

In Kiev, the culprit is seen as Moscow, and maybe Trump, too. Analysts there point to a weekend telephone conversation between Trump and Russian President Vladimir Putin, which was followed by the upsurge in fighting. The battles, continuing Thursday, have since killed dozens of soldiers and civilians on both sides. Some suggest that Trump may have given the Russians some sort of go-ahead signal for aggression, while others argue that Mr. Putin is simply testing the limits of what he can get away with under a Trump-led US.

"There is a fear [in Kiev] that Russia and the US might come to some sort of agreement behind Ukraine's back," says Vadim Karasyov, director of the independent Institute for Global Strategies in Kiev. "There is still hope that we can fulfill the Minsk II accord, but much will depend on the position the US is going to take."

Ukrainian experts allege the Kremlin is engineering the situation to press for sped-up US-Russia negotiations, which they fear would be conducted largely on Moscow's terms.

Putin's spokesman, Dmitry Peskov, suggested as much on Wednesday. "As for the current aggravation at the engagement line, then, this is, perhaps, another reason for the quickest resumption of a dialogue and cooperation between Russia and America, including in the interests of solving and disentangling the Ukrainian knot," Mr. Peskov said.

Analysts in Moscow argue that Kiev is deliberately escalating the war to mobilize political supporters in the US and force Trump to reiterate the former Obama administration's unqualified support for Ukraine. So far, that does not seem to be happening. A State Department statement issued Tuesday expressed concern about the rising violence and reaffirmed support for the Minsk peace process, but conspicuously refrained from placing the onus of responsibility on Russia, as previous statements almost ritually did.

"The name of the problem is Donald Trump," says Sergei Strokan, foreign affairs columnist for the Moscow daily Kommersant. "He appears to be keeping his options open on Ukraine, and this worries people in Kiev very much. It looks like this new upsurge in fighting is designed to force the issue. After all, when there's bloodshed happening, an answer has to be given. The Ukrainians are very afraid that the US will stop blaming Russia for the situation in Donbass. And while Europe is in disarray, this lack of solid support for Kiev could become the new normal."

In an interview with a pro-rebel publication, the commander of the rebel Vostok Battalion, Alexander Khodakovsky, similarly complained that Ukrainian forces had launched an unexpected offensive due to "hidden" political reasons.

Impasse over Donbass

Whatever position Trump comes to, there seems little doubt that the Minsk II accord is failing, largely due to the longstanding unwillingness in both Kiev and the two Russia-backed rebel republics to implement its terms.

The Russian hope – and Kiev's deepest fear – is that Trump might do a deal with Putin, effectively consigning Ukraine to a Russian "sphere of influence," which would put an end to Ukrainian dreams of aligning with the European Union and NATO.

In what is certainly another sign of mounting worries in Kiev, Ukrainian President Petro Poroshenko announced Thursday that he will call for a referendum in Ukraine on NATO membership, even though NATO has made clear it will not consider the issue anytime soon.

Over the past three years Ukraine has built up its military forces, and now claims an overall strength of 250,000 men, with about 100,000 of them stationed in the eastern war zone. Ukrainian military budgets have almost doubled in the past five years. On a visit to Donbass in December, Mr. Poroshenko boasted that Ukraine now has "the strongest army in Europe." Although anti-war sentiment appears strong among Ukrainians, some in Kiev have begun to talk about liberating the rebel-held territories by military means.

"Our Army is looking for ways and approaches," says Sergey Gaiday, head of the Gaiday Agency, an independent Kiev political think tank. "When the conflict began three years ago, our Army was in a critical state and had no experience. Now Putin's action have led to the creation of a new type of Ukrainian Army, professional and well-equipped, with battle experience."

Get the Monitor Stories you care about delivered to your inbox. By signing up, you agree to our Privacy Policy

Whoever is to blame for triggering the current violence, some analysts say, this dangerous moment illustrates that without concerted international focus on Ukraine's conflict, the default position of both Kiev and the rebel republics is war.

"Ukraine is not going to implement the Minsk agreements unless there is substantial outside pressure," says Mikhail Pogrebinsky, director of the independent Kiev Center for Political Studies.