北韓地理位置的特殊性，使其在學術與外交實務領域，常以北韓、美、中的「戰略三角理論」分析三方關係。戰略三角理論中，「孤雛」（outcast）被視為比較各類互動模式之最差情形，而國家作為戰略三角的行動者，往往也對此一地位避之唯恐不及。不過，觀察北韓自金正恩上任以來，採取諸如加速發展核武、頻繁試射彈道導彈等挑釁美、中等周邊國家作為，使其與美、中關係快速惡化，甚促美中開始合作制裁，北韓在與中、美之「戰略三角」中似自願落入「孤雛」。2017年開始，北韓透過改善與俄羅斯、南韓關係打開國際困境，陸續會晤中、美領導人，而原本讓北韓陷入孤雛的核武、洲際導彈轉瞬變成與美、中等各方談判桌上的重要籌碼，加上金正恩對內政權掌握具壟斷性、透過改善南韓關係等逐漸緩和對外政策操作戰略多角等方式，在本文所觀察的2017年底至2019年年中期間，北韓在與美、中之「戰略三角」地位獲得快速回升。 Because of North Korea unique location, both in the academic and reality areas, usually use the strategic triangle theory to analysis the North Korea-U.S.-China's relationship. Strategy triangle theory regards the “outcast” is the worst status in all kinds of model. To be a part of the strategic triangle, states always prevent outcast status. However, since Kim Jongun assume the leader of N.K., he took provocative measures to U.S., China and other nearby countries, such as missile launches, nuclear tests and so on. The relationship with China or U.S. turns bad because of the N.K. provocative behaviors, not only promotes China and U.S. coordinate N.K. sanction, but also brings N.K. to be the “intending”outcast in the strategic triangle. Out of the world expectation, N.K. begins to improve the relationship with Russia, South Korea, U.S., and China. From the end of 2017 to the mid-2019 of this writing, the nuclear weapon which make N.K.to be outcast is being the key chip on the negotiation table, and it status in the strategic triangle promoting.
