Looking at the tables at https://ourworldindata.org/grapher/foreign-aid-given-as-a-share-of-national-income most of the countries that "once ruled or colonized" less wealthy parts of the world give more than the US as a GDP %. Portugal is about the only exception.
It's the "richest large country/largest rich country" problem.
It's the "richest large country/largest rich country" problem.
Comments
US aid is (was) critical simply because the US is so rich, even as the US spends less than many other states.