The United States is a major commercial powerhouse in the global market and has a moral responsibility to help with poverty in less-fortunate countries. While the United States has a substantial number of local citizens living under the poverty line, they could prevent much of the exploitation of the poorest populations in countries that US-based companies use for manufacturing goods cheaply. It would be as easy as forcing companies exploiting cheap labour overseas to pay at the minimum a living wage to their foreign employees or contractors. This would greatly improve poverty levels for those individuals without putting the weight of the cost on individual taxpayers but rather forcing companies to eat a portion of their profits to uphold standards that is expected in the United States.
Yes, the US should help with poverty in other countries. Wealth distribution is severely uneven across the world and many people battle for day-to-day survival in impoverished countries across the globe. As one of the world's richer nations, the US should help even out global wealth distribution by aiding these less fortunate states, in the hopes that one day, these other states will no longer suffer from poverty.
If the U.S. spends billions on unnecessary wars, it should be able to spend a fraction of that on countries in dire need of aid. It simply is the right thing to do and that doesn't change just because a country has gotten itself into so much debt. Those reasons seem to fall by the wayside if spending means more power for us, but often becomes an "obstacle" if it means helping others. If one wants to see the monetary benefits, not only does it save lives, but it can go into projects to help those people become more independent and raise the standard of living in the country. Eventually this can build up their economy and lead to trade and gains back to the US.
If the U.S. can spend trillions of dollars in the name of helping overthrow governments in countries like Afghanistan and Iraq, then it should certainly be able to spend a fraction of that helping to alleviate poverty in other countries. I can't stand the patriotism of U.S. politicians, who constantly say things like "We need to do what's best for the people of the United States." I believe they should say "We need to do what's best for the world." We're all humans, and we should help each other more, instead of dividing along national lines.