Which document must be considered for policy aimed at international cooperation in defense?

The Arms Export Control Act (AECA) is essential for establishing policies regarding international cooperation in defense because it provides the legal framework for the export of defense articles and services to foreign governments and international organizations. This act outlines the conditions under which defense exports can occur, ensuring they align with U.S. national security interests and foreign policy objectives.

By regulating the transfer of military equipment and technology, the AECA plays a crucial role in fostering partnerships and alliances with international partners. It also ensures that the U.S. maintains control over its defense capabilities while promoting security cooperation with allied nations.

While the other options provide important insights into defense policy, they do not specifically address the regulations governing international arms transfers and defense cooperation in the same way as the AECA. The Joint Staff Guidance focuses on military operations and strategies, the National Security Strategy outlines broader national security goals, and the Defense Acquisition System Manual pertains to procurement processes rather than the specifics of international military cooperation. Thus, the AECA is the correct document to consider for policy aimed at international cooperation in defense.