In Chinese political discourse, 单边主义 is a term loaded with negative meaning. It stands in direct opposition to the officially promoted concept of 多边主义 (duōbiānzhǔyì), or multilateralism, which emphasizes international cooperation, consensus-building, and respect for global institutions like the United Nations. When Chinese officials or state media criticize a country for practicing 单边主义, they are accusing it of being a global bully—selfish, arrogant, and disruptive to world peace and stability. This reflects a core principle in Chinese foreign policy that emphasizes a “harmonious world” (和谐世界 - héxié shìjiè) and respect for national sovereignty, viewing unilateral actions as a form of hegemonic overreach. A useful comparison is to the Western, particularly American, concept of “decisive leadership” or “American exceptionalism.” An action that one side might frame as necessary and decisive leadership to protect national interests could be immediately labeled by the other as dangerous and destabilizing 单边主义. Understanding this term is key to decoding the perspective presented in Chinese news and official statements regarding international affairs.
单边主义 is almost exclusively a formal term used in specific contexts. You will not hear it in casual, everyday conversation unless the topic is specifically international politics.
The connotation is always negative. No country would describe its own policy as 单边主义. It is a label of accusation, implying recklessness and a disregard for the global community.