若一個國家承諾不參加軍事同盟（除抵抗攻擊外），而且也不承擔可以間接地使它捲入戰爭的義務，就會被稱為中立國。中立國可分戰時中立，或是永久中立。不是國家自己喊說我要當永久中立國就會立即生效，必須要取得國際間的承認，才能達到「永久中立國」的實質效果。例如亞洲唯一一個永久中立國土庫曼便是經過聯合國承認，瑞士的永久中立國身分則是經由維也納會議確認。
成為永久中立國的最大好處就是不受軍事侵擾，可穩定發展經濟，瑞士便是最好例子。另外也可吸引一些國際組織或金融機構進駐，或是舉辦多國峰會，與重要國家維持良好關係。

目前國際間普遍公認的永久中立國如下：
・教廷（梵諦岡）
・列支敦斯堡
・瑞士
・瑞典
・芬蘭
・愛爾蘭
・奧地利
・馬爾他
・哥斯大黎加
・土庫曼

When a state promises not to enter into military alliances (unless for defense purposes) and does not assume obligations which may indirectly involve it in warfare, it is defined as a neutral country. A neutral country can either maintain its non-combatant status during a specific war or can permanently stay neutral toward all future conflicts. This status is not determined by self-proclamation; de facto permanent neutrality requires formal international recognition. For example, the status of Turkmenistanas a permanent neutral state, the only one in Asia, is recognized by the United Nations. Switzerland’s status as a permanently neutral country was also made official by the Congress of Vienna. 

One of the best perks of being a permanently neutral country is that a state can stay out of military conflicts, and this in turn ensures stability for better economic development. Switzerland is the best example of this case. Additionally, countries with neutral status have great appeal to international organizations or financial institutions when selecting a location for setting up its operations and make an ideal location for multinational summits which provide an excellent opportunity to maintain good ties with key powers.