Unilateral Use of Force in International Law: A Study on Just War Theories in Modern Age

冷战结束后，国际社会更多地看到个别国家单方面使用武力的情况。1999年，北约出于人道主义目的轰炸了南斯拉夫。2001年9.11事件发生后，美国对阿富汗采取了军事行动，被称为“反恐战争”。2003年，它开始了伊拉克战争，因为伊拉克据称拥有大规模杀伤性武器，但至今仍未发现。“新正义战争理论”就是为这些单边行动而提出的。其中之一是“人类安全”。它可能有损国家安全，同时也可能为使用武力进行人道主义干预的单方面行动辩护。一个被称为“失败国家”的国家，如果不能或不愿意保护人民的人权，就是不能承担“保护责任”的国家。保护责任的概念是加拿大委员会为允许个别国家在极端情况下使用武力而提出的。现在，支持单方面使用武力的各种理论都被提出为现代正义战争理论，但不使用武力原则的唯一例外是《联合国宪章》第五十一条中的自卫权。使用不符合自卫要求的武力可被理解为根据《联合国宪章》的非法行动。阿富汗的情况说明了自卫的正当理由。最重要的问题是，武装袭击是否发生在美国行使自卫权之前。必须质疑的是，阿富汗是否在很大程度上参与了9/11恐怖袭击。但毫无疑问，恐怖袭击的受害国有权对另一个仅仅为恐怖分子提供庇护所的国家采取自卫军事行动，因为那个国家在很大程度上没有参与恐怖袭击。

After the end of the Cold-War, the international society witnesses more often cases of unilateral use of force by individual states. In 1999, NATO bombed Yugoslavia for the humanitarian purposes. After the 9.11 incident in, 2001, the United States conducted the military operation against Afghanistan, which was called "the War on Terror." In 2003, it began the Iraqi War because Iraq allegedly possessed WMDs, which have never found out yet. The "new just war theories" were advanced for these unilateral actions. One of them is "human security." It may serve against the security of state, while it may justify unilateral action for humanitarian intervention using force. A state called "failed state" which is not able to or willing to protect human rights of peoples is considered as one which cannot take "responsibility to protect." The concept of the responsibility to protect is advanced by the Canadian commission for allowing use of force by individual states in an extreme case. Now various theories supporting unilateral use of force are put forward as modern just war theories.However the only one exception to the principle of non use of force is the right of self-defence in Article 51 of the Charter of the United Nations. Use of force which does not meet the requirements of self-defence can be understood as illegal action under the UN Charter. The Afghanistan case was illustrative for the justification of self-defence. The most important question is whether armed attack occurred before the right of self-defence was exercised by the United States. It must be questioned whether Afghanistan was substantially involved in the terrorist attacks on September 11. But it is not arguable that a victim state of the terrorist attack is entitled to take military operation in self-defence against another state which just gives a shelter to the terrorists, because that state is not substantially involved it the attacks.