American aid can actually help other countries change the conditions of their prisons. Not all the people in prison in other countries are hardened criminals, some are in jail because the justice system in their country is flawed. If the prisons are reformed then eventually the justice system might be reformed too, which would be a good thing.
America should not aid foreign countries in prison reform because we are already lacking in the containment and safety in our own prison systems. By aiding foreign countries in prison reforms means that we need to be sure our own systems are flawless so that the guidance and money is well spent if they choose to send aid to those countries.
America cannot save the entire world. We already have aid programs that send billions of dollars to developing countries. These programs help them with basic things like food, shelter and public health. Prison reform is small in comparison to these things. Also, going to prison is avoidable. Establishing private property and a rule of law is important, but cleaning up the prisons of the world is not America's job.
We have major problems in our own prison system. Focus our efforts there. Our prisons are overcrowded with low-level offenders such as drug users. They are places of violence and discrimination. We should be working to find other alternatives to prison for most offenders, and concentrate on improving prison conditions across the board.