Stocks across the globe closed lower Friday after President Donald Trump unveiled his plan for levying tariffs on trading partners, threatening to upend decades of international cooperation.

Global stocks are sliding after President Trump’s new tariff announcement, with S&P 500 futures down nearly 1% and major indices worldwide falling. Analysts warn the true impact of these tariffs will hit the U.S. economy in the coming months through higher costs for companies and consumers. Import taxes are now at their highest since the 1930s.