Claudio Descalzi is CEO of the Italian energy giant Eni. As Russia’s assault on Ukraine roils European energy markets, companies like his are hustling to keep up with demand. Descalzi says the war (along with Covid) exposed how inelastic the demand for energy is: consumers and heavy industry need fuel whether there’s a war (or pandemic) on or not. Getting it to them while simultaneously exploring more sustainable resources is the challenge facing huge suppliers like his.