U.S. stocks drifted to a mixed finish on Thursday as U.S. President Donald Trump’s tariffs taking effect on dozens of countries had only a muted effect on markets worldwide.

Donald Trump warned that if any court strikes down his reciprocal tariffs policy, then it could plunge the United States into an economic collapse reminiscent of the Great Depression of 1929.

President Donald Trump began levying higher import taxes on dozens of countries Thursday, just as the economic fallout of his monthslong tariff threats has begun to create visible damage for the U.S.