THE timing was ominous. A day after the first, seemingly cordial telephone conversation between Donald Trump and Vladimir Putin, the residents of Avdiivka, a small town on the Ukrainian side of the conflict line with Russian-backed separatists, heard the echoes of heavy artillery fire. The conflict that Russia started in Ukraine in 2014 has been partly frozen over the past two years. But on January 29th it flared up with renewed force.

Three days later, on February 1st, the bodies of seven Ukrainian soldiers killed in the fighting were brought to Kiev. Maidan, the city square that was the site of the country’s 2014 revolution, once again swelled with people. Social media were filled with messages of support for soldiers and calls to collect supplies for victims, along with videos of shelling by Russian Grad rockets. Ukrainian soldiers received text messages seemingly sent by the Russian side: “You are just meat to your commanders”. Since then other Ukrainian positions along the front line have been attacked, and the death toll is rising.

Following the flare-up, the American ambassador to the Organisation for Security and Co-operation in Europe, which monitors the ceasefire, blamed “combined Russian-separatist forces” for starting the attacks. Ukrainian forces have been creeping forward into the “grey zone” in recent months, seizing positions in several small towns. The rebels might have felt it was an opportune moment to hit back.

Whoever started the fighting, its victims are the 16,000 civilians in Avdiivka, who for days were cut off from electricity in temperatures of -20°C, and those in the rebel-held territories, many of whom lack water. The violence underscores the difficulty of implementing the Minsk Two ceasefire agreement, signed in February 2015, which the two sides interpret differently. For Kiev and its Western backers, the agreement is a path for Ukraine to reassert control over its east and close its border with Russia, followed by a decentralisation of power to its regions. Russia, however, sees the agreement as a way of retaining control over eastern Ukraine, keeping the border open and demanding that Kiev recognise Donbas as an autonomous region within Ukraine. This would give Russia permanent influence over Ukraine’s future.

From Ukraine’s point of view, the violence was a warning to its American and European allies, several of whom are considering lifting sanctions against Russia. “Who would dare talk about lifting the sanctions in such circumstances?” asked Petro Poroshenko, Ukraine’s president, who cut short a visit to Germany to attend to the crisis. Mr Poroshenko later said he would call a national referendum on joining NATO—which Russia considers a red line and NATO itself does not want.

Doubting the Donald

Many Russia-watchers think Mr Putin may have stoked the conflict to test his new American counterpart. Mr Trump has promised better relations with Moscow. Mr Putin may have decided to probe his willingness to turn a blind eye to Russian actions in Ukraine, the two countries’ main point of conflict. The Russian government says Ukraine was discussed in their telephone conversation.

In the past, significant escalations of fighting were quickly met by the White House or the State Department with strongly worded statements condemning Russian aggression and supporting Ukraine’s territorial integrity. This time it took the State Department two days to say it was “deeply concerned”; it did not mention Russia. This response was duly noted in Moscow. “Washington does put the blame on the [separatist] republics, does not express support for Kiev and does not say a word about Russia’s role,” Rossiiskaia Gazeta, the official government newspaper, wrote jubilantly.

The Kremlin also noted the American failure to react to the news that Alexei Navalny, an opposition leader and anti-corruption campaigner, would be tried again on trumped-up charges. Mr Navalny pledged to run against Mr Putin in next year’s presidential elections, but is now likely to observe Mr Putin’s re-election from a prison cell.

Correction (February 3rd): An earlier version of this article misattributed a statement by the American ambassador to the OSCE. This has now been corrected.