The best way for a county to implement foreign policy is?

Multilaterally.

Explanation: Multilaterally is fundamental to politics and the economy.

The concept can be perceived as a form of cooperation, especially with regard to international diplomacy and actions that allow countries to respect limits.

These boundaries that countries face are at social, economic, political and national and international security levels.

Multilaterally is the result of an important historical process that can be observed over the decades. Once states realized that they could not alone solve issues that could harm other nations.

the doctrine of nullification recommended that states living inside the union have the one-sided, inalienable ideal to void any law made by the national government that could be esteemed illegal.

the united states was shaped based on a general agreement among its individual states. hence, it is inferred that under the hypothesis of invalidation, since the states are the establishment of the union, they have the ability to referee and disprove unlawful laws.