In which of the following conflicts would the U. S. intervene according to the Powell Doctrine?
A. a national civil war in Russia between ethnic groups

B. a country is harboring terrorists responsible for attacks on the U. S.

C. a fight between Canada and Great Britain over who should have trade rights to Mexico

D. European nations arguing over climate regulations

B.  a country is harboring terrorists responsible for attacks on the U.S.

Explanation:

The Powell Doctrine is a term that is used for a policy that is primarily focused on defense of the country and preventing attacks on the country, usually by using military force. In order for a military attack to be approved though numerous things have to be taken in consideration, examined, and answered.

From the presented scenarios, the Powell Doctrine would enable the U.S. the intervene in a country is harboring terrorists responsible for attacks on the U.S. Such examples in the past few decades have been the war in Afghanistan because of Al-Qaeda, and the war in Iraq, also because of Al-Qaeda. A military intervention also occurred in Iraq and the neighboring Syria because of the rise of the terrorist organization ISIS among other reasons.

a goverment for the people by the people

b: the establishment clause  

b: socialism