An unexpected decision by President Donald Trump has once again shaken global markets.

After a night of reflection, he announced yesterday, February 21, on social media that he had increased global tariffs from 10% to 15%, dashing Europe’s hopes for easy gains and confirming the uncertainty that has reigned in the economy since his return to the White House.

According to Trump’s statement, the decision is based on a “full and detailed” review of the Supreme Court’s decision, which he called “incredible, poorly written, and extremely un-American.”

The US president announced that the tariffs would reach the maximum legally allowed level of 15%, targeting countries that he said had “exploited” the US for decades.

This decision uses Section 122 of the Trade Act of 1974, a legal provision that has rarely been used for such purposes.

The problem is that the measure expires in 150 days and Trump must seek congressional approval to extend it. Given the difficulty of securing a majority vote in the House of Representatives and the possibility that some Republicans may not support it, the administration is planning an alternative based on Section 301, which provides for investigations into unfair trade practices and the application of tariffs to punish them.

Some exceptions are expected for strategic goods, such as rare earths, and for countries like Mexico and Canada, with which the US has existing agreements.

The situation has worried Europe.

German Chancellor Merz declared that “the only poison for economies is this continued uncertainty over tariffs,” while French Trade Minister Nicolas Forissier warned that Europe has the means to react and respond to economic or political pressures from other countries.

In this situation, China seems to benefit, as its exports are increasing.

And when Trump visits Beijing at the end of the month, the “weapon” of tariffs may be weaker and less reliable, following the Supreme Court’s decision.