A system of trade, diplomacy, or relations between two countries or groups rather than involving many parties at once.
From 'bilateral' (Latin 'bi-' two + 'lateralis' side) plus the suffix '-ism' indicating a system or practice. Became common in 20th-century international relations vocabulary.
During the Cold War, bilateralism was everywhere—the US and USSR conducted most of their serious negotiations one-on-one rather than through the United Nations, which completely shaped world politics.
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