Nuclear weapons, which have become one of the key pillars of maintaining the so-called “long peace” in the postwar world, were first developed in the United States during World War II. This achievement was the result of a collaborative effort by an international group of scientists, working under American leadership and supported by the USA industrial and technological resources. From the outset, secrecy was a central concern—not only regarding technical details, but the very existence of the program. Even the term “Manhattan Project” was deliberately chosen to obscure the nature of the initiative. This paper examines the methods employed by the Manhattan Project leadership to maintain secrecy throughout the development of the atomic bomb. It also explores how these efforts influenced the pace of the project, the emergence of the unique “secret city” culture, and the safety protocols governing work at various sites. The analysis draws primarily on personal sources, including memoirs and interviews with project participants. While the question of secrecy has occasionally been addressed in broader studies of the Manhattan Project, it has never been the subject of focused academic inquiry. In Russian historiography it is often acknowledged but seldom explored in depth too. This study aims to help fill that gap. In light of ongoing international tensions and continuing efforts by non-nuclear states to obtain nuclear capabilities, research into the history of nuclear development and proliferation remains particularly relevant. The paper concludes that secrecy was not merely an operational necessity, but a formative factor in the very structure and management of the Manhattan Project. This imperative shaped the project’s organization and contributed to a range of scientific, engineering, and administrative challenges. Nonetheless, the project met its objectives within a reasonable timeframe without any major security breaches.
Ilia Alexandrovich Ripak (Fri,) studied this question.