In the year since US President Donald Trump declared “Liberation Day” and unleashed high global tariffs, many have largely stopped paying attention to the constantly shifting trade policy announcements out of Washington. Tariffs, originally set to eye-wateringly high levels of up to 50%, have since fallen dramatically to an effective average of just over 8%.¹

Despite this apparent good news, trade with the United States remains disrupted with four “known unknowns” set to create more confusion in the coming weeks.² In each instance, it is possible to “know” an issue is coming to a head without clearly being able to predict how it will unfold, making the outcome “unknown.”

The first “known unknown” is that the timelines for two ongoing Section 301 investigations are rapidly concluding. These investigations, opened against 60 different countries that trade with the United States, are looking into alleged unfair trade practices for structural excess capacity and production in manufacturing sectors, as well as failure to take sufficient action to prevent forced labor.³

The first case identified 16 partners and opened a comment period running until 15 April. By 8 April, the index for submitted comments ran to 48 pages.⁴ The hearing for the case begins on 5 May.

The second case, against the same set of 16 countries plus an additional 44 trade partners, also has an ongoing comment period which also ends on 15 April. As of 8 April, the index listing comments ran to 27 pages.⁵ The hearing to consider the case is set for 28 April–1 May.

Once the hearings are concluded, the US Trade Representative’s Office (USTR) could provide its recommendations to the White House as early as mid-May. Unlike past legal authorities used by this administration, Section 301 does not specify trade remedies, limit potential tariffs, or provide timelines for resolution.⁶ As structural excess capacity and forced labor are not covered by any other US trade agreement, the administration has wide latitude under Section 301 to impose unilateral remedies.⁷

Within a matter of weeks, USTR and the White House could reimpose tariffs or other trade restrictions at any level against any of the named trade partners. Even countries that are excused from the upcoming accusation of unfair trade practices, however, could find themselves back in the crosshairs, as Section 301 allows relatively easy future adjustments to scope and coverage.

The second known unknown are changes ahead under a different legal authority in the US, Section 232 for national security. The US just adjusted one set of Section 232 cases for metals and issued a new Section 232 for pharmaceuticals.⁸

The metals tariffs have been a source of growing concern for companies. The compliance costs of dealing with US imports containing steel, aluminum, and copper have been substantial. Until now, firms have had to separate out the “metals” from non-metal content in products. The metal bits have been assessed 50% tariffs.⁹

The rule change made on 2 April consolidated three existing cases into one.¹⁰ Items made entirely of covered metals still receive 50% tariffs on import, starting on 6 April. Items containing metal are now given a flat rate of 25% tariffs on the full value of the product, without the need to unravel metal and non-metal content. Listed items with minimal metal content may be exempt from Section 232 tariffs.¹¹

One rule change, however, moves this apparent consolidation of metals tariffs into a new category of “unknowns.” Specifically,

“The Secretary [of Commerce] and the Trade Representative are authorized to include additional derivative articles within the scope of the tariffs imposed pursuant to Proclamation 9704, as amended; Proclamation 9705, as amended; or Proclamation 10962 whenever they jointly determine that imports of a derivative aluminum, steel, or copper article have increased in a manner that threatens to impair the national security; contribute to the national security threats found in Proclamation 9704, Proclamation 9705, or Proclamation 10962; or otherwise undermine the objectives of the actions taken to address the national security threats found in Proclamation 9704, Proclamation 9705, or Proclamation 10962. This authority shall allow metal containers to be included in the scope of the metal tariffs, even if they are filled with items that will not be subject to steel, aluminum, or copper tariffs.”¹²

In other words, the revised metals policy creates more uncertainty about how goods may be included or excluded from coverage going forward. This type of rule change could be applied to other existing Section 232 cases, like autos and auto parts or lumber, as well as included in upcoming Section 232 announcements.

The third set of known unknowns is the continuing legal saga resulting from Trump’s trade authority. Trump started imposing tariffs on trade partners in January 2025 under the International Economic Emergency Powers Act (IEEPA). The Supreme Court found the use of tariffs under IEEPA to be illegal on 20 February 2026.¹³

Since then, the issue of managing tariff refunds has been handed back to the Court of International Trade (CIT), a specialized Court to handle economic matters. The CIT has ruled, in no uncertain terms, that importers are due refunds with interest.

This known fact, however, is combined with a great deal of unknowns, particularly around the potential timing of any refunds and the processes needed to arrive at the result.

To simplify a very complex set of legal maneuvers, the judge in the CIT case has instructed US Customs and Border Protection (CBP) to expedite refunds. CBP has said it will comply, but it needs to complete a new set of internal processes and procedures to do so.

Until this year, CBP was not set up to process refunds electronically, but relied on issuing paper checks. Additionally, most importers did not have their own electronic accounts to manage interaction with Customs.

CBP has promised that its new system, CAPE (Consolidated Administration and Processing of Entries), will be ready, starting on 20 April to automate processing of IEEPA tariff refunds for importers.¹⁴

There are still significant unknowns regarding refunds, including uncertainty over whether CBP can meet its own timeline (originally set for 45 days) to get the system up and running. Firms have been slow to set up their own accounts and, given the relative newness of information demands, companies are finding many incomplete details or inconsistencies in their own records for past entries.

There is a growing concern in the supply chain communities that CBP will not simply automate refunds, but will seek to use the process to investigate a range of past practices. This could significantly delay any refunds and, ultimately, could lead to heavy fines or penalties. Even extremely compliant firms have struggled to manage rapid and inconsistent rule changes over the past year.

There is an ongoing concern over the timing of imports relative to potential refund dates as well. As many of the original IEEPA tariffs were paid more than a year ago, these entries have been liquidated, or marked as resolved. It remains unclear exactly how CBP and firms will address the oldest known tariff payments.

Finally, any tariff refunds are set to go to the importer of record. Some of these firms have ceased operations in the face of tariff costs. Others have passed on tariff costs directly to customers. Many firms worked with their exporters to share the tariff burden, and not all have clear contractual terms that captured these decisions. In short, once tariff refunds start getting processed, there is likely to be continuing uncertainty and potential legal battles over who gets the money.

IEEPA refunds are not the only ongoing legal battle over tariffs. The CIT is also managing a dispute over the status of the “temporary” tariffs in place for a balance-of-payments problem.¹⁵ When IEEPA was overturned by the Supreme Court, the US quickly pivoted to using Section 122 and imposed 10% tariffs on all global trade partners. These will expire in July. The case before the Court is whether or not the US faces a balance-of-payments problem which would justify the use of tariffs.

The last known unknown is the status of the array of bilateral trade arrangements the US has made with various trade partners. These agreements were drafted in the context of IEEPA tariffs. While the US continues to argue that the deals still stand, the “reciprocal” tariff rates covered in each agreement is no longer applicable.

At this point, most imports to the US from bilateral trade partners are facing 10% tariffs under Section 122 (or, for covered sectors, Section 232 tariffs). Most of the bilateral arrangements do not include provisions to address current or future Section 232 tariffs. None include language to limit the use of Section 301 tariffs or other remedies. Thus, as the US pivots to new, more durable statutory authority for tariffs, the utility of the existing bilateral trade deals may continue to fall.

Trade partners have been left to grapple with uncertainty. Section 301 investigations only increase the pressure on foreign governments. The timelines for potential new changes emanating from the US are short. It remains unknown what might happen in the near term, but the likelihood of new trade adjustments is high.

The past year has delivered significant trade disruption. The overturn of IEEPA by the Supreme Court has not led to calmer waters. Trade will remain contested, with at least four issues likely to reach inflection points within a matter of weeks or months.