OPINION: With US tariff ruling, trade war enters new phase

By Kim Sang-cheol Posted : February 24, 2026, 09:41 Updated : February 24, 2026, 09:41
Kim Sang-cheol
SEOUL, February 24 (AJP) - Two months into the new year, uncertainty continues to mount, unsettling businesses and consumers alike. What matters as much as what changes is what holds steady — yet unexpected shocks keep emerging and how governments and companies respond will determine what lies ahead.

A new variable has hit global trade. The U.S. Supreme Court ruled that U.S. President Donald Trump's reciprocal tariffs and fentanyl-related tariffs imposed under the International Emergency Economic Powers Act (IEEPA) were illegal. The court said that while IEEPA grants a president the authority to "regulate" imports during a national emergency, it does not explicitly authorize "tariffs."

The Trump administration wasted no time finding alternatives. Citing Section 122 of the Trade Act, it announced a global tariff of 15 percent for up to 150 days. It has also begun weighing "Super 301" as a tool to target specific countries with retaliatory tariffs.

Attention is now turning to what comes next. With 64 percent of Americans opposing Trump's tariff policy, U.S. industry has welcomed the ruling as a positive sign for the economy. Financial markets, however, remain unsettled: the dollar fell 0.2 percent against major currencies, while U.S. stocks rose.

Trump is expected to quickly work to keep tariff measures going. The tariff battle could also become a political setback for him in November's midterm elections, yet aggressive efforts to regain momentum are likely to continue, as voter sentiment may do little to constrain him.

The next stage is how other countries respond and how carefully they tread. Rash moves could backfire, as Trump still has powerful options at his disposal. A sudden action could trigger Super 301 measures that even the Supreme Court might not be able to block.

China appears quietly pleased, judging that Trump's bargaining power has weakened and that Beijing can hold out longer. The EU is observing cautiously, even as it maintains that conditions may not worsen. Canada remains broadly optimistic, while Mexico is wary that the U.S.-Mexico-Canada Agreement could face new fallout. Japan has avoided issuing a formal statement, reaffirming its commitment to promised U.S. investments and emphasizing that sector-specific tariffs such as those on autos or steel and aluminum are not affected by the ruling.

South Korea has taken a stance similar to Japan's, signaling a cooperative approach toward Washington. Anxiety persists after Trump recently warned he could raise South Korea's reciprocal tariff from 15 percent to 25 percent over delays in fulfilling investment pledges. Concerns are heightened because Trump often relies on brinkmanship when cornered. Overall, the current mood in South Korea–U.S. relations leaves little room for complacency.

The calculus is complicated by Japan's new government under Prime Minister Sanae Takaichi, which has moved closer to Washington while sharpening its confrontation with China.

Given Northeast Asia's security environment, South Korea cannot easily ignore U.S. economic pressure amid China's growing influence, North Korea's nuclear threat and its deepening military ties with Russia.

There have been signals that the role and function of U.S. forces stationed in the region could change. Japan is accelerating its efforts to become a country capable of waging war, while scenarios of a Chinese invasion of Taiwan persist, drawing Taiwan closer to the U.S.

South Korea's stance remains uncertain. Within the government, a debate is growing between those who prioritize the U.S. alliance and those who favor greater strategic independence including closer ties with China.

There is disagreement over South Korea's investment pledges to the U.S., following the ruling, but the two are separate issues. To protect its national interests, South Korea should first create conditions for profitable investment in the U.S. market, diversifying supply chains, shifting energy import sources, and helping South Korean companies capture new opportunities there.

In areas Washington is rushing to rebuild, such as semiconductors and shipbuilding, South Korean firms are not the only capable players, with Taiwan and Japan possessing nearly comparable technology.

Even if South Korea is excluded, U.S. rebuilding would not face major problems. If South Korea hesitates to cooperate with the U.S. or Japan due to concerns about North Korea or China, the fallout could spill over into the economic sphere as well. South Korea–U.S. relations remain on thin ice.

* This article, published by Aju Business Daily, was translated by AI and edited by AJP.

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