Question

One of the foreign affairs powers of congress allows it to control _____.

Answer 1

Your answer is Foreign Commerce.

Answer 2

Foreign commerce

Such power is part of the enumerated powers of the Congress which is outlined in Section 8, of the article I of the U.S. Constitution, it states the following:

The Congress shall have power (...) to regulate commerce with foreign nations, and among the several states, and with the Indian tribes

This means that one of the Congress' duties is to control the sale, marketing, trade, and traffic of goods or commodities between the United States and other nations.