Is terrorism ever morally justified? How should historical and cultural factors be taken into account in judging the morality of terrorist acts? What are the ethical limits of state counter-terrorism? For three decades the Provisional Irish Republican Army waged an 'armed struggle' against what it considered to be the British occupation of Northern Ireland. To its supporters, the IRA was the legitimate army of Ireland, fighting to force a British withdrawal as a prelude to the re-unification of the Irish nation. To its enemies, the IRA was an illegal, fanatical, terrorist organization whose members were criminals willing to sacrifice innocent lives in pursuit of its ideological obsession. At the centre of the conflict were the then unconventional tactics employed by the IRA, including sectarian killings, political assassinations, and bombings that devastated urban centres - tactics that have become increasingly commonplace in the post-9/11 world. This book is the first detailed philosophical examination of the morality of the IRA's violent campaign, and of the British government's attempts to end it. Written in clear, accessible prose, it is essential reading for anyone wishing to acquire a deeper understanding of one of the paradigmatic conflicts of the late 20th century.