The commonly held view that an ethical approach to arms sales is desirable but ‘unaffordable’ because jobs and exports are at stake is challenged by Samuel Brittan. He argues that it arises from a failure to understand the circular flow of income, the fallacy of a ‘lump of labour’ and a long discredited mercantilist view of trade. The author contends that on moral and economic grounds, arms sales should not be subsidised or officially promoted in any way, and governments should be much stricter in enforcing bans on sales to dubious regimes.