This chapter examines the intelligence-based strategy and tactics of the British Army during its deployment to Northern Ireland, officially termed Operation Banner and lasting from 1969-2007. The experience of British Army intelligence in Northern Ireland raises a number of practical, legal and ethical questions. In analysing operations it is important to periodize rather than thematize security in Northern Ireland because examining the conflict in terms of themes does not capture the development of tactics, the context of the time and the sets of choices that were made. A historical approach allows an appreciation of both effectiveness and ethics. The success was very much dependent on the army settling into a specific political context which then produced a strategic context in which intelligence and specialist units became particularly important in what will be termed a Very Low Intensity Conflict (VLIC). Informant intelligence was employed by Tasking and Coordination Groups (TCGs) to conduct a variety of operations after debate and discussion.