On Sunday, a Ukrainian drone attack destroyed more than 40 Russian planes deep in Russia’s territory.

Codenamed “Spiderweb”, the undertaking by Ukraine’s Security Service, involved more than 18 months of planning and and was personally overseen by Ukraine’s President Volodymyr Zelenskyy.

AP News reported that in the span of a few hours nearly a third of Moscow’s strategic bomber fleet was destroyed or damaged with cheaply made drones sneaked into Russian territory.