Section 232 of the Trade Expansion Act of 1962 authorizes the president to adjust imports of goods — through tariffs, quotas, or other restrictions — when the Secretary of Commerce determines that those imports threaten national security. The Commerce Department conducts an investigation, and the president then has broad discretion to act on the findings. Section 232 has historically been used sparingly but was invoked by the Trump administration for steel and aluminum in 2018 and expanded to pharmaceuticals, semiconductors, lumber, and other industries in 2025-2026.