R&S: Why should first-world countries be morally forced into helping the third world?

Is it the taxpayer's fault of the first-world countries why the third world is in such a bad shape? No, it isn't. Anytime a hard working, contributing member of society says enough is enough and actually wants their tax-dollars to be used for their own country's best interests, they get called a callous and selfish person. Third world countries should be left to their own devices, and we shouldn't be morally forced into helping them and giving them our money for nothing in return.