Bosnian Foreign Minister Igor Crnadak rejected the notion that the EU may be less attractive for aspiring countries, arguing that membership remained one of the strategic pillars of Bosnia's foreign policy.

Indeed, he said that one of the few good things to had come out of the migration crisis was that it made people in the EU understand that for major problems, "you don't just need the EU, you need Europe".

"Enlargement is not only in the interest of the applicant countries but also of the EU. The European idea is not lost," Crnadak stressed.

Reva Goujon of the US security analytics firm Stratfor meanwhile analysed the US trade and foreign policy. She said that after a long period that was rather hazy, the world was now shifting to "great-power competition" again.

The US is engaged in competition with China and, to a lesser extent, Russia. "For Europe and others caught in the middle, there will be a lot of consequences... The US is trying to rebalance and the tactics [US President Donald Trump] is using can be quite disruptive."

Nevertheless, Goujon said, Europe is still highly relevant, for example in the Middle East and for containing Russia, and the US wants Europe to hold together. "The last thing the US wants is Europe to succumb to its demons ... It needs Europe as an ally."

Thomas Greminger, secretary general of the Organization for Security and Cooperation in Europe (OSCE), made a case for continued multilateralism despite all the pressure the concept has faced in recent years.

He proposed that some things needed to be done by multilateral institutions themselves. "We need to make it a business case, we need to tell ordinary people why multilateral approaches matter when it comes to solving global problems."

According to Greminger, one solution would be to take a cue from the populists, who have been using marketing very smartly, but neither should multilateral institutions "shy away from looking at instruments and mechanisms developed in recent decades and see whether they are still efficient. They should be ready to evolve."