@johnscarf , YES -- to utilize foreign tax credit (suspended / carryover or new), you need foreign income. And NO, the credit and income does not have to be from the same country -- in your particular case , even though the income that generated the tax credits came from Peru, the carry-over could be used against foreign taxes paid on income from another country. The only other way to utilize the credit is to use as deduction when you itemize.
Does this answer your query ?