On October 16, 2018, the Trump administration issued Memorandum 2018-23050, which delegated specified authorities granted under Section 1604(b) of the John S. McCain National Defense Authorization Act for Fiscal Year 2019. This memorandum transferred particular powers from the President to designated executive branch officials, enabling them to exercise defense-related authorities without requiring presidential sign-off on each individual decision. The legal mechanism relied on statutory delegation language already embedded in the McCain NDAA, allowing the administration to streamline the exercise of these authorities across relevant departments and agencies.

The primary effect of this delegation was to distribute decision-making power over defense matters to career and political appointees within the Defense Department, State Department, and other relevant agencies. Rather than centralizing authority at the presidential level, the memorandum created a framework whereby officials at multiple levels could act on matters previously requiring direct presidential authorization. This expanded the practical scope of executive action on defense policy without new legislative authority, simply reorganizing how existing statutory power would be deployed.

This delegation fits within a broader pattern of the Trump administration asserting and distributing executive power over foreign military policy and defense matters. Subsequent actions, including the 2026 fast-tracking of $8.6 billion in arms deals to Middle Eastern partners and Israel that bypassed standard congressional review, and the deployment of additional military forces to enforce an Iran maritime blockade, demonstrate how delegated authorities became operational tools for executing the administration's increasingly assertive foreign policy agenda. The delegation established procedural mechanisms that would later enable rapid decision-making on military aid, troop deployments, and regional military operations.

No significant legal challenges or congressional blocks to this memorandum appear on record, as it operated within the existing statutory framework. The delegation itself was a routine exercise of presidential authority in structuring the executive branch, though its practical effects merged with more controversial subsequent actions that tested the boundaries of executive power in military affairs and foreign policy.