Trump declares that global tariffs will rise from 10% to 15%, taking effect immediately, marking a dramatic escalation in his ongoing trade battle just one day after a major legal blow from the U.S. Supreme Court.

In a move that stunned both markets and policymakers, President Donald Trump announced Saturday that he would increase global tariffs to 15%, up from the 10% rate he had introduced a day earlier. The decision came swiftly after the Supreme Court ruled against his previous use of emergency powers to impose sweeping trade duties.

Supreme Court Limits Emergency Tariff Powers

On Friday, the Supreme Court issued a 6-3 ruling stating that Trump had overstepped his authority by using the International Emergency Economic Powers Act (IEEPA) — a 1977 law intended for national emergencies — to justify imposing tariffs on trading partners.

The ruling effectively blocked the administration’s attempt to use emergency powers as a broad trade weapon. Trump responded forcefully, calling the decision “deeply disappointing” and publicly criticizing several justices — including some he had appointed — for siding against his policy.

Rather than retreating, however, the president pivoted.

A Shift to Trade Law Section 122

Following the court’s decision, Trump announced on Truth Social that he would immediately raise the worldwide tariff rate to 15%, the maximum allowed under Section 122 of U.S. trade law. Unlike the emergency powers statute, Section 122 grants presidents authority to impose temporary tariffs of up to 15% for 150 days, though congressional approval is required beyond that period.

Originally, Trump had planned to implement a 10% global tariff effective Tuesday at 12:01 a.m. ET. The White House has not clarified whether the revised 15% rate will take effect on the same timeline.

According to Erica York, vice president of federal tax policy at the Tax Foundation, a 15% tariff would push the effective tariff rate for the year to around 6% of total imported goods — a significant burden on trade flows and supply chains.

A Broader Pattern of Aggressive Trade Moves

This latest escalation fits into a broader strategy Trump has pursued since last year. His administration previously imposed sweeping “reciprocal” tariffs, raising duties as high as 50% on countries such as India and Brazil. Tariffs on China at one point surged to 145%.

In addition, the White House has relied on Section 232 investigations — typically justified on national security grounds — to levy broad tariffs on steel, aluminum, copper, lumber, furniture, automobiles, and car parts.

Another available pathway is Section 301, which allows the U.S. to investigate and penalize countries deemed to be engaging in unfair trade practices that harm American businesses.

Experts note that further tariff hikes — potentially reaching 50% on certain imports — could invite challenges under World Trade Organization agreements, intensifying global trade tensions.

Trump is expected to address global trade directly during Tuesday’s State of the Union address.

Who Wins and Who Loses in the 15% Tariff Era?

While the 15% rate represents an increase from Trump’s initial 10% proposal, it may actually reduce pressure on some countries compared to earlier tariff threats.

Countries That May Benefit

Nations such as Brazil, Canada, China, India, Indonesia, Mexico, and South Africa had previously faced tariffs as high as 50% under emergency powers. For them, a standardized 15% duty could mean relative relief.

Kyle Handley, an economics professor at the University of California, San Diego, described countries like Brazil and India — which negotiated trade deals with the Trump administration — as “temporary winners.” However, he cautioned that industry-specific tariffs could still be imposed under alternative legal authorities.

Countries Facing Higher Costs

On the other hand, countries such as Argentina, Australia, Saudi Arabia, and the United Kingdom may see their trade conditions worsen under the new framework.

The reshuffling of tariff burdens highlights the uneven nature of Trump’s trade strategy, where outcomes vary significantly by region and industry.

Impact on U.S. Businesses and Consumers

Major retailers including Walmart, Target, Costco, and Amazon could benefit from the revised structure if it lowers rates compared to previous tariff levels. Appliance sellers and home improvement chains like Home Depot, Lowe’s, and IKEA — which were hit hard by earlier tariffs — may also see some breathing room.

Steel and aluminum tariffs remain unchanged, while the adjustment of reciprocal tariffs on auto parts could offer relief to automakers such as GM, Ford, and Toyota.

However, the outlook for American consumers remains uncertain.

Even if tariffs are reduced in certain areas, prices may not fall quickly. Imported goods already sitting in warehouses were purchased at higher rates, meaning any price relief would likely be gradual. Treasury Secretary Scott Bessent expressed skepticism about whether consumers would see meaningful refunds or cost reductions.

“There won’t be too much relief,” Handley noted, pointing to ongoing uncertainty in global trade negotiations.

A New Phase of Trade Uncertainty

Perhaps the biggest shift is not just the tariff rate itself, but the narrowing flexibility available to the president.

The Supreme Court’s ruling signals limits on executive power in trade matters. Analysts suggest that the era of rapidly negotiating individualized deals country-by-country and industry-by-industry may be fading.

Businesses now face a complex and evolving landscape — one shaped by legal constraints, political maneuvering, and economic uncertainty.

What remains clear is that Trump declares that global tariffs will rise from 10% to 15%, taking effect immediately, reinforcing his commitment to a protectionist trade agenda even in the face of judicial resistance.

The global trade battle is far from over — but its rules may be changing.