The sudden interruption on Wednesday by Ukraine of the delivery of part of the Russian natural gas transiting through its territory came as a reminder of how vulnerable Europe's energy supply remains.
But also how, despite the war, Russia and Ukraine remain linked by the geography of the energy distribution networks, and forced to cooperate at a minimum, including in the midst of conflict.
Find the report by Adrien Jaulmes, special correspondent in Kiev:
Why, despite the war between Russia and Ukraine, the gas trade continues
Gleb Garanich/REUTERS
