Mekong Brief is biweekly trade intelligence on Vietnam, written from Ho Chi Minh City for buyers, exporters, and the people advising them.

A US trade court ruled the 10 percent tariff on Vietnamese exports unlawful. On May 7, the Court of International Trade held 2-1 that Section 122 -- the legal basis for the current 10 percent global tariff -- exceeded presidential authority, finding that the underlying proclamation failed to identify a true balance-of-payments deficit (Holland & Knight, May 2026). The injunction applies only to the named plaintiffs; for everyone else, the tariff is still being collected at the border. The Trump administration appealed to the Federal Circuit the next day.

Vietnam was named the United States' most serious intellectual property concern. The April 30 Special 301 Report from USTR elevated Vietnam to "Priority Foreign Country" status -- the highest tier in the IP enforcement framework, and the first such designation in 13 years (USTR, April 30, 2026). The label triggers a 30-day window for USTR to decide whether to open a formal Section 301 IP investigation. Hanoi responded fast: a nationwide IP enforcement campaign launched May 7, with a directive to lift IP enforcement actions 20 percent year-on-year.

Vietnam's overall four-month trade deficit hit $7.11 billion. Vietnam's imports grew 28.7 percent year-on-year through April; its exports grew 19.7 percent. The reversal from years of consistent surpluses gives Washington a fresh talking point in the US-Vietnam framework agreement negotiation.

Garment and footwear exports are at record levels -- one year after the April 2025 tariff round was supposed to redirect sourcing away from Vietnam. The Section 301 forced labor investigation now in hearings could reset that math, with apparel and footwear among the most exposed sectors.

The 10 percent tariff on Vietnamese exports to the United States expires by statute on July 24, 2026. It was imposed February 24 -- four days after the Supreme Court ruled the prior tariff regime unlawful.

Section 122 of the Trade Act of 1974 lets the president impose temporary import restrictions to address a balance-of-payments deficit, capped at 15 percent and 150 days unless Congress extends them (19 U.S.C. § 2132). The Trump administration invoked it after the Supreme Court ruled in Learning Resources, Inc. v. Trump on February 20 that the prior tariff regime -- imposed under the International Emergency Economic Powers Act -- exceeded presidential authority (SCOTUS, February 20, 2026; White & Case, February 2026; CRS IF10209, April 27, 2026). The 150-day clock from February 24 runs out July 24.

Section 122 itself is now under separate court attack. On May 7, the US Court of International Trade -- a different federal court from the Supreme Court -- ruled 2-1 that the Section 122 tariff exceeded presidential authority, finding that the underlying proclamation failed to identify a true balance-of-payments deficit (the kind of destabilizing trade-and-capital shortfall Section 122 was originally written to address) (Holland & Knight, May 2026). The court issued a permanent injunction limited to the named plaintiffs -- two private importers and the State of Washington. The Trump administration filed its appeal to the Federal Circuit on May 8. For Vietnamese exporters' US customers, the practical situation is unchanged in the near term -- the 10 percent continues at the border. But the Trump administration's runway to lock in a successor regime just got shorter.

What replaces it is the question driving three concurrent USTR investigations, each capable of generating new tariffs on Vietnam:

Track 1: Special 301 / IP. The April 30 designation of Vietnam as a Priority Foreign Country in the annual Special 301 Report on IP gives USTR until around May 30 to decide whether to open a formal Section 301 investigation -- the general trade-enforcement mechanism that can impose country- or sector-specific tariffs distinct from any framework agreement (USTR, April 30, 2026).

Hanoi has signaled urgency on two fronts. First, on May 5, Prime Minister Lê Minh Hưng appointed Standing Deputy PM Phạm Gia Túc to head the government's Working Group on adapting to US economic and trade policy adjustments -- a leadership upgrade for the team managing the US relationship (Lao Dong, May 5, 2026). Second, a nationwide IP enforcement campaign launched May 7, directing ministries and provinces to increase IP enforcement actions 20 percent above May 2025 levels (Vietnam News, May 7, 2026). VASEP has issued emergency compliance guidance to seafood exporters; the association estimates roughly $2 billion of Vietnamese seafood exports could be exposed if the Special 301 designation produces a formal Section 301 investigation. Vietnamese state media has framed the situation in the language of risk -- "Vietnam risks US tariffs over IP failures" -- which reads as cooperation rather than pushback. USTR's reaction over the next 18 days will tell us whether it landed.

Track 2: Section 301 manufacturing overcapacity. Public hearings ran May 5–8 in the investigation USTR launched in March 2026 covering 16 economies, Vietnam being one of them. USTR has cited Vietnam's cement overcapacity at "nearly 100 percent of domestic demand" alongside trade-surplus evidence in electronics, machinery, footwear, apparel, furniture, and steel (Federal Register 2026-05214, March 17, 2026).

Track 3: Section 301 forced labor. A parallel investigation covering 60 economies ran public hearings April 28 – May 1, focused on labor practices in textile and apparel supply chains; Vietnamese garments are explicitly in scope.

Unlike Section 122, none of these three Section 301 tracks carries a statutory rate cap or an expiration. Whatever USTR finds is what stays.

The October 2025 framework agreement was negotiated against the trade tools the Trump administration had in 2025. The 2026 toolkit -- Section 122, Special 301, two Section 301 investigations -- emerged after the framework was signed. Vietnam's bilateral deal is now structurally exposed to mechanisms that weren't on the table in October.

Practical implications. For exporters, the framework agreement is no longer the ceiling. For buyers running China+1 sourcing, Vietnamese product exposure under any of the three tracks is asymmetric across HS codes -- electronics, machinery, and steel face the highest combined risk; agricultural and processed foods the lowest.

Eight weeks, four decisions, no rate caps on the replacements. The rest of this issue is what to watch, and what to do about it.