Efforts to secure, transport, and employ weapons of mass destruction primarily fall under which category?

The focus on securing, transporting, and employing weapons of mass destruction is primarily categorized under nuclear security. This category encompasses all measures and actions designed to prevent unauthorized access or theft of nuclear materials and protect against nuclear terrorism. It includes the development and implementation of strategies to ensure the integrity and safety of nuclear weapons and associated materials throughout their lifecycle, from storage to transport to use.

While nuclear disarmament and nuclear risk reduction refer to reducing the number of nuclear weapons and mitigating the risk associated with their potential use, they do not directly address the operational aspects of securing and transporting these weapons. Nuclear proliferation concerns the spread of nuclear weapons and technology to states not recognized as Nuclear Weapon States, which is a different aspect of nuclear weapon management.

Therefore, nuclear security is the correct category as it directly pertains to the safeguarding and management of nuclear arsenals, ensuring that they do not fall into the wrong hands or are misused in any capacity.