Luuk Snijder

The first victim of conflict is often the truth. Using 261 manifestos from real-world conflicts, we show that attacking leaders frequently misrepresent strategic intentions in their calls to arms: they often hide their primary objective for exploitation behind claims of self-defense. Using experiments, we show that self-defense rhetoric in real war speeches, true and false, is readily believed by naïve participants (n = 252, pre-registered), and increases support for the leaders’ stated cause. Furthermore, in intergroup contest experiments (n = 312; pre-registered), leaders frequently invoke the need for self-defense even when outgroups pose no actual threat. This leads followers to increase their costly contributions to fight non-threatening outgroups, making their (deceptive) leaders prevail in increasingly intense and wasteful intergroup conflicts. Our findings elucidate when leaders resort to false signalling, why they do so, and how it can escalate conflicts that benefit warring leaders at significant cost to society.