Ukraine launched an ambitious counteroffensive last June, aimed at reaching the Sea of Azov to split the Russian military in half. The frontline has stalled: Ukrainian soldiers have been unable to advance. In an interview with The Economist, the commander-in-chief of the Ukrainian armed forces Valeriy Zaluzhny, said his military was facing a "stalemate."

Why has Ukraine's counteroffensive faltered? Sylvie Kauffmann, an editorialist at Le Monde, helps us understand.