Provide for the common defense- this responsibility of the Constitution most relates to the United States’ interactions with other nations.
Explanation:
Every nation has its own constitution with its preamble which describes the basic fundamental features of a country. Like United states in its constitution has a responsibility of provide for the common defense which is related with other nation.
Congress has the power of declaring war at the crisis moment. To promote nation's security congress, president and other higher officials has the power to declare war in favor of country's interest. If any powerful country suddenly attack United States then it can declare combinely war against that country to protect nation's interest.
