multilateralism

noun

1. (countable, uncountable)Unbiased trade between nations, in contrast to bilateralism.
2. (countable, uncountable)A system by which nations consult others in matters of foreign policy, by way of organisations such as the United Nations.

   “Trump’s national security adviser, John Bolton, a lifelong opponent of multilateralism and its institutions, had pushed for a hardline position, particularly on the role of the IMF.”