He can increase tariffs, cut off funding and limit aid to foreign countries because he knows that, without the US, those organizations and governments would be unable to sustain themselves.
I know others who have been aggressively finding alternative suppliers both in the US and in countries that are less exposed to higher tariffs.
Or the American companies that have been historically unable to sell their milk, cheese, butter and chicken in Canada because they face existing tariffs exceeding 200%.
Neither are e-commerce businesses that buy products from China, food service companies that sell Mexican produce or energy companies that rely on oil supplies from up north.
Others are simply finding ways to cut costs by doing things like reducing their property footprint or investing in technology and AI to offset the increase in the prices of materials.