Perfidy
（重定向自Perfidiously）
In the context of war, perfidy is a form of deception in which one side promises to act in good faith (such as by raising a flag of truce) with the intention of breaking that promise once the enemy is exposed (such as by coming out of cover to capture the "surrendering" enemy). Perfidy constitutes a breach of the laws of war and so is a war crime, as it degrades the protections and mutual restraints developed in the interest of all parties, combatants, and civilians.