An unconditional surrender is a surrender in which no guarantees, reassurances, or promises (i.e., conditions) are given to the surrendering party. It is often demanded with the threat of complete destruction, extermination or annihilation.

Announcing that only unconditional surrender is acceptable puts psychological pressure on a weaker adversary, but it may also prolong hostilities. A party typically only demands unconditional surrender when it has a significant advantage over their adversaries, when victory is thought to be inevitable.

In modern times, unconditional surrenders most often include guarantees provided by international law. In some cases, surrender is truly accepted unconditionally; while in other cases terms are offered and accepted, but forces are declared to be subject to "unconditional surrender" for symbolic purposes. This type of surrender may also be accepted by the surrendering party under the expectation of guarantees agreed to informally.

Examples

Banu Qurayza during Muhammad's era

After the Battle of the Trench, in which the Muslims tactically overcame their opponents while suffering very few casualties, efforts to defeat the Muslims failed, and Islam became influential in the region. As a consequence, the Muslim army besieged the neighbourhood of the Jewish Banu Qurayza tribe, leading to their unconditional surrender. All the men, apart from a few who converted to Islam, were executed, while the women and children were enslaved.[1][2][3][4][5] The historicity of the incident has been questioned.[6]

Napoleon Bonaparte

When Napoleon Bonaparte escaped from his enforced exile on the island of Elba, one of the steps that the delegates of the European powers at the Congress of Vienna took was to issue a statement on 13 March 1815 declaring Napoleon Bonaparte to be an outlaw. The text includes the following paragraphs:

Consequently, as Napoleon was considered an outlaw when he surrendered to Captain Frederick Maitland of HMS Bellerophon at the end of the Hundred Days, he was not protected by military law or international law as a head of state and so the British were under no legal obligation to either accept his surrender or to spare his life.[8] However, they did so to prevent him from being a martyr and exiled him to the remote South Atlantic island of Saint Helena.[citation needed]