I agree with the previous posts. The U. S. is already serving as a self-appointed world policeman. The last thing we need to do is forgive our debts to countries who could then turn around and become our enemy. We need to reduce our debt--not increase it.
To be honest with you, the only debt the United States needs to be concerned about is our own. We've forgiven far to many debts in the past, which is a small part of why our country has a bleak economic outlook.
This is only true if these countries have governments that would (once out of debt) do the right things with the money that they get. I doubt that this is the case for most countries. In too many countries, if we forgave their debt, corrupt leaders would simply run up a new debt and the people would be no better off.