Trump claims that it was due to America's generosity and protection that other countries benefited and raised their living standards, while the United States itself gained nothing.
[T]he crisis of soft power risks accelerating the decline of [U.S.] power in the world, activating and speeding up centrifugal dynamics that might otherwise have taken years to fully manifest.
Trump and his advisers have repeatedly insisted that the U.S. president can pretty much do whatever he wants and that the pesky Congress need only be consulted rarely.