How have presidents used Section 232 (1962) and Section 301 (1974) in 2018-2019 tariffs?

Executive summary — What the 2018–2019 tariffs actually did and how the president used two old statutes

The core finding is that the Trump administration invoked Section 232 ^[1] to impose national‑security tariffs on steel and aluminum (25% on steel, 10% on aluminum, announced March 2018 with selective exemptions), and invoked Section 301 ^[2] to levy multiple rounds of tariffs on Chinese imports after finding unfair technology‑transfer and IP practices, reaching several hundred billion dollars in covered goods. These actions produced a complex mix of product exclusions, phased lists with varying rates, legal debate over executive authority, and measurable economic ripple effects, including retaliatory tariffs and higher costs for downstream U.S. firms ^{[3] [4] [5] [6]}.

1. How the president used a Cold War law to justify metals tariffs — national security invoked

The administration relied on Section 232 of the Trade Expansion Act of 1962 to justify tariffs on steel and aluminum, asserting that certain imports threatened U.S. national security and therefore warranted import relief. The measures imposed 25% on steel and 10% on aluminum beginning March 23, 2018, and initially excluded several trading partners including Canada, Mexico, South Korea, Australia, Brazil and the EU; some exemptions were later extended or made permanent while others remained subject to tariffs ^[3]. The government established an exclusion request process for businesses seeking relief from the duties; approval rates varied, with one source reporting a roughly 49% approval rate for steel exclusion requests in a snapshot of the process ^[4]. Critics argued the national‑security justification was a stretch and produced trade frictions; proponents argued the tariffs supported domestic producers and helped revive the U.S. metals sector ^[6].

2. Section 301: the targeted campaign against China’s trade practices

The administration used Section 301 of the Trade Act of 1974 to respond to a formal USTR investigation that found Chinese policies on technology transfer, intellectual property, and innovation to be unreasonable and discriminatory, justifying tariffs on a broad swath of Chinese exports. The measures came in multiple tranches across 2018–2019, covering roughly $250 billion to $370 billion of imports depending on the accounting and exact lists, with tariff rates ranging from about 7.5% to 25% and additional adjustments during later reviews ^{[4] [5]}. The USTR issued lists of products in stages and allowed exclusion petitions for some items, reporting a ~34% approval rate for the first tranche of Section 301 exclusion petitions in one dataset ^[4]. The Section 301 campaign was explicitly framed as correcting unfair practices rather than national security, marking a different statutory and rhetorical basis than Section 232 ^{[5] [6]}.

3. Numbers, scope, and timeline — reconciling different tallies

Sources vary in counting the universe of affected imports and the timeline, but they converge on the same broad picture: Section 232 took effect in March 2018 for steel and aluminum, with country‑specific treatments evolving thereafter; Section 301 unfolded across 2018 and 2019 in several tariff lists that cumulatively targeted hundreds of billions in imports and included multiple rates and review windows ^{[3] [5] [7]}. One dataset describes roughly $250 billion initially targeted under three tranches, while another compiles lists amounting to approximately $370 billion across four lists; later administrative reviews and additional policy tools have changed coverage and rates since 2019 ^{[4] [5]}. The disparity reflects how analysts count initial lists, later additions, and whether subsequent adjustments are included.

4. Economic effects and political controversy — winners, losers, and legal fights

The tariffs produced mixed economic effects: domestic steel and aluminum producers gained price support and industry advocates credited the tariffs with aiding recovery, while downstream manufacturers and consumers faced higher input costs and uncertainty. Retaliatory tariffs from trading partners harmed certain U.S. exporters, creating sectoral losers even as some producers benefited ^{[6] [3]}. Legally and politically, the measures sparked debate over executive authority—critics called Section 232 national‑security claims an overreach and questioned Section 301’s broad use, while supporters emphasized unilateral tools to address perceived unfair practices. Multiple reports and government reviews documented the policy choices, exclusion processes, and trade responses, underscoring the complexity of evaluating net benefits ^{[6] [8]}.

5. What the official records and reviews emphasize — transparency, exclusions, and unresolved questions

Government reports and analyses published around 2018–2019 and later emphasize procedural points: both statutes permitted exclusion petitions and administrative reviews, which produced variable approval rates and added procedural complexity; official timelines and USITC work documented the actions and their immediate trade impacts ^{[7] [4]}. Analysts note unresolved questions about long‑term industry outcomes, the precise effect of tariffs on innovation and supply chains, and the precedent set for future presidents using national‑security or trade‑remedy statutes. The body of official and analytic material from 2018–2019 provides clear factual markers for what was done; interpreting whether those markers represent successful policy depends on different economic and political value judgments that the records themselves do not settle ^{[8] [7]}.