THE HAGUE (Reuters) – The 58 world leaders gathered in The Hague to discuss nuclear security were asked to explore how they would react to a nuclear attack or accident by taking part in a simulation set in a fictional country called Brinia.

It was a big departure from the formats typically adopted at major multilateral summits, and some of the leaders said on Tuesday they were impressed at the exercise set up by their Dutch hosts.

“It was a new, helpful experience,” German Chancellor Angela Merkel said after the exercise, which was held on Monday. She said the exercise had tested leaders’ reactions to nuclear incidents and terrorist attacks.