Why is it unconstitutional for a state government to ban products imported from a foreign country, despite that country engaging in activities not condonable by that state?

What will be an ideal response?

The Commerce Clause of the U.S. Constitution gives the federal government the exclusive power to regulate commerce with foreign nations. This is referred to as the Foreign Commerce Clause. Direct and indirect regulation of foreign commerce by state or local governments that unduly burdens foreign commerce violates the Commerce Clause and is therefore unconstitutional. The federal government could enact a law that forbids another country from doing business in the United States if that country engages in activities that are not condoned by the United States. A state, however, could not enact a law that forbids a foreign country from doing business in that state if that country engages in activities that are not condoned by that state.