The photographs and flowers outside the Ukrainian Embassy in Warsaw bear witness to the dramatic events in Ukraine over the past 18 months. A large photograph of Kiev’s Independence Square at the height of the Maidan protests is on the wall of Andrii Deshchytsia’s office. “I’m in there somewhere,” he says cheerfully, pointing into the seemingly endless crowd.

After president Viktor Yanukovych fled Kiev in February 2014, Deshchytsia became acting foreign minister. “We were working 20 hours a day,” he says. By responding to the change of power in Kiev with aggression, first in Crimea and then the Donbas, “Russia questioned, in a completely uncivilised way, Ukraine’s right to choose its future”, he says. In his opinion the conflict can be ended “by combining all the possible means” – military and diplomatic, economic sanctions and political pressure – on the Kremlin.

Deshchytsia’s ministerial posting was only temporary. In October he took up his current role in Warsaw. It is his third stint here; his first was as press secretary in the 1990s and later as an adviser. “I received a very warm welcome this time from my friends, and now my new friends,” he says. Official relations between Ukraine and Poland have existed for more than two decades but now for the first time he notices very broad social support for Ukraine in Polish society. The flowers and candles outside the embassy were not just brought by local Ukrainians but also Poles, he points out.

For Deshchytsia, who hails from Ukraine’s western edge, home is not too far away. Warsaw is less than 400km from Lviv, where he studied before doing a master’s at Canada’s University of Alberta (he also has a PhD in political science). There is no language barrier: he speaks excellent Polish, in addition to English, Russian and his native Ukrainian.

“Each time I come to Poland I see a different Poland,” he says. Things keep changing for the better; for instance, there are more cycle lanes in Warsaw now. For Poland in the early 1990s, after the fall of Communism, the prospect of EU membership was “the light at the end of the tunnel”. Ukraine is still waiting for Brussels to give it that light, Deshchytsia adds.

The appointment of the Italian foreign minister Federica Mogherini as the EU’s foreign affairs and security policy chief last November has brightened the bureaucratic ranks. The 41-year-old set out to prove herself with a packed travel schedule and some strong appointments, as well as easing Tony Blair out of his Middle East envoy role.

“She is showing she can make decisions, that she can get rid of people who she thinks haven’t delivered,” says Silvia Francescon of the European Council of Foreign Relations. Francescon believes Mogherini’s appointment will be no panacea for Brussels’ male-dominated culture. “On this she’ll have to lead by example.”

As leader of the Organisation for Security and Co-operation in Europe (osce), Serbia’s influence lasts to the end of the year. Foreign minister Ivica Dacic has made the Ukraine crisis his priority as osce chairman and is well placed to play honest broker. Serbia has retained its ties to Russia, made progress to EU membership and recognised Ukraine’s territorial integrity.

It is a tricky balance, especially with Brussels putting Belgrade under pressure to impose sanctions against Russia. But as long as Serbia can remain on friendly terms with all the players it may make a difference. The challenge for the music-loving Dacic is to get everyone singing the same tune.

Europe’s deteriorating relationship with Russia has prompted renewed interest in an EU Energy Union. More than half of the EU’s energy is imported but every country currently does its own deals.