US Supreme Court Reviews Legality of 'Trump Tariffs'. AP=Yonhap News.

Korea Investment & Securities predicted on the 6th that even if the US Supreme Court rules against the government in the 'Trump tariffs' case, agreements with major trading partners like Korea, with whom deals have already been finalized, will not be invalidated, though adjustments to specific clauses will be inevitable.

In a report on the same day, researcher Park Ki-hoon pointed out that if the Trump administration loses the case, it may be possible to impose limited tariffs through existing trade law provisions, but tariffs based on the International Emergency Economic Powers Act (IEEPA) would lose their effect.

He analyzed, "If the Trump administration's Plan B fails to secure negotiation power comparable to that under IEEPA, refunds of some of the already collected tariffs will be unavoidable," adding, "Assuming the ruling is finalized in the first half of (next year), an amount equivalent to approximately $200 billion, or 10% of the US's annual fiscal deficit, may have to be returned."

He further stated, "While agreements with major trading partners such as Korea, Japan, and the EU (European Union), with whom deals have already been concluded, will not be nullified, adjustments to specific clauses will be inevitable due to the change in legal basis," and "Temporary stability in trade policy uncertainty could escalate again."

He pointed out, "The instability of the tariff system will expand trade and exchange rate volatility, but there will be a time lag before the actual impact materializes," and "This matter needs to be recognized as a potential risk factor rather than an immediate drastic adjustment."

He added, "As the market's focus could shift depending on the future ruling and policy response direction, this issue is judged to be an event that should be carefully reflected in future strategy planning rather than in short-term responses."

Yesterday (local time), the US Supreme Court began hearings to determine the legality of the broad tariffs imposed by President Donald Trump on countries around the world, including Korea.

The legal determination of whether imposing tariffs, a key tool of President Trump's economic and foreign policy, falls within the president's authority is now being reviewed, and the Supreme Court's decision is expected to have significant repercussions domestically and internationally.

Previously, lower courts, including the International Trade Commission (USCIT), which handled the first instance, and the US Court of Appeals for the Federal Circuit in Washington D.C., which oversaw the second instance, ruled that the Trump administration's use of emergency powers to impose tariffs worldwide was illegal.

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