President Trump has made significant changes to the international system in just 50 days, including switching sides in the Ukraine war, voting against traditional allies, and damaging trust among NATO allies. The future of the international system and America's role in it is uncertain, with some believing that these changes are permanent and others hoping that the old system will survive. Trump's actions suggest a return to 19th-century great-power politics, negotiating with other major powers and disregarding lesser powers. The Trump administration is eroding the old order without offering a clear vision for a new system.