A light sandwich lunch is served at 12.55pm. All welcome.

What are the moral constraints on the exercise of unconventional force—that is, force conducted by a state outside of its sovereign territory but not during war? We have an extensive body of theory regarding the ethics of conduct in war, but little of substance for the unconventional context. The enquiry is important because there is an increasing preference among policy-makers for the use of unconventional force in pursuit of humanitarian and national security objectives. US drone strikes in Yemen are an example; so is espionage; so are assassinations; so is cyberwar (usually). I defend two theses in answer. First, there are some actions that, because they are always impermissible, are a fortiori also impermissible in unconventional contexts. Torture is an example. More interestingly, so is targeting the innocent. Second, outside of that restriction, while it is not the case that ‘anything goes’, nearly anything can. What ‘goes’ must be within the constraints of any conventions which govern unconventional force. These can be extremely permissive. In a slogan, spies and special forces play by big boys’ rules.

Dr Tom Simpson is Associate Professor of Philosophy and Public Policy at the Blavatnik School of Government, University of Oxford, and a Senior Research Fellow at Wadham College. He came to Oxford from Cambridge, where he was a Research Fellow and received his degrees (BA, MPhil, PhD). His doctorate was entitled Trust on the Internet and was sponsored by Microsoft Research. Between degrees Dr Simpson was an officer with the Royal Marines Commandos for 5 years. He served in Northern Ireland as a Troop Commander with 45 Commando; as aide-de-camp to the senior UK General in Baghdad, Iraq; and as an intelligence and operations officer with HQ 3 Commando Brigade RM when it led the UK Task Force in Helmand Province, Afghanistan. The academic life is undoubtedly a privilege, but he remains conflicted about its sedentary nature.