governments of rich, "developed" countries are often interested in the health of other countries. they are especially interested in the health of neighbor countries. the reasons for this are many: if they have extra resources, they may want to share them with their neighbors; but also they may want to stop spread of diseases from their neighbor country across the border. for example, the united states is a richer country than mexico and has little problem with measles (in children) or rabies (in mammals) in the interior, but along the border with mexico these diseases are more common.