In a world punctuated by civil and global conflict, it seems almost quaint to promote peace as a weapon of choice. Even in more progressive quarters, an explicit identification with pacifism seems to evoke nostalgia for a time when the enemy was obvious and the mission supposedly self-evident. But in recent decades the threat has become more nebulous, as has the relationship between defence, government, and the arms industry. Ideological differences, rather than territorial disputes, are much harder to resolve. A drone strike, regardless of its intended specificity, will always incur – to borrow from army parlance – a significant amount of ‘collateral damage’.