What method of pest control operates on the principle that "the enemy of one's enemy is one's friend"?

The correct answer is biocontrol

Biological control

An area that portrays that all species of plants and animals have natural enemies, which attack various stages of life of their targets. Among the natural enemies there are very diverse groups such as insects, viruses, fungi, bacteria, spiders, fish, amphibians, reptiles, birds and mammals.

answer; (you have the right of way);

hello,

answer: a federal government has final authority on interstate/inter provincial  and international affairs, a confederation is one where the central/national government or authority is governing body what does not have final say over the same matters. hopefully this and i will try again if you don't like this answer : )

best of luck!