In Chapter 5, we reflect on the ethical challenges of irregular warfare. In special operations doctrine, irregular warfare most often involves working ’through, with or by’ foreign guerrillas (unconventional warfare) or foreign counter-guerrilla forces (foreign internal defence). Engaging in armed conflict through proxies can seem like a cheap and low-risk option to policy-makers, but it also contains the potential for conflicts of interest and priorities inherent in all principal–agent relationships. If a powerful state (the principal) feels it has achieved its war aims, can it simply withdraw from a fight in which their proxies (the agent) and their SOF partners are still engaged? Likewise, proxies have incentives to mislead sponsor states as to their capabilities, intentions, and commitment to ethical warfighting. To what extent are SOF morally accountable for the ethical conduct of the foreign combatants whom they advise?