In this letter, physicist Igor V. Kurchatov, the scientific director of the Soviet nuclear project, writes to secret police chief Lavrenti Beria, whom Stalin had given principal responsibility for the atomic effort. Prodded by his own scientists and by intelligence reports of the secret Anglo-American atomic enterprise, Stalin had initiated a small-scale Soviet nuclear weapons program in late 1942-early 1943. But the level of support political leaders had given the project failed to satisfy Kurchatov, who pleaded with Beria for additional backing.