A new report written by a former Pentagon official who helped establish United States policy on autonomous weapons argues that such weapons could be uncontrollable in real-world environments where they are subject to design failure as well as hacking, spoofing and manipulation by adversaries.

In recent years, low-cost sensors and new artificial intelligence technologies have made it increasingly practical to design weapons systems that make killing decisions without human intervention. The specter of so-called killer robots has touched off an international protest movement and a debate within the United Nations about limiting the development and deployment of such systems.

The new report was written by Paul Scharre, who directs a program on the future of warfare at the Center for a New American Security, a policy research group in Washington, D.C. From 2008 to 2013, Mr. Scharre worked in the office of the Secretary of Defense, where he helped establish United States policy on unmanned and autonomous weapons. He was one of the authors of a 2012 Defense Department directive that set military policy on the use of such systems.

In the report, titled “Autonomous Weapons and Operational Risk,” set to be published on Monday, Mr. Scharre warns about a range of real-world risks associated with weapons systems that are completely autonomous.