International Institute for Strategic Studies - The modern law of self-defence (video) and the government has published the text of the speech - HERE. See also The Guardian 12th January 2017 - 'Specific' terror evidence not necessary for RAF drone strikes.
Mr Wright said that he welcomed the opportunity to speak on an
international question which is one of the most serious any government
can face – when is it lawful for a state to use force – always a last
resort and only where it is necessary. He chose to set out how the UK
applies the long-standing rules of international law on self-defence to
our need to defend ourselves against new and evolving types of threats
from non-state actors.
In September 2015, the RAF used a drone strike to kill Reyaad Khan and others who were in Syria at the time. This attack was considered in a number of posts - View from the North: A Killing in Syria (8th September 2015); Death by Drone - concerns and questions (15th September 2015). The killing by the USA of Mohammed Emwazi ("Jihadi John") was the subject of a post on 14th November 2015 - Reported killing of Mohammed Emwazi.
Parliament's Joint Committee on Human Rights issued a report in May 2016 - The Government's policy on the use of drones for targeted killing - Second Report of Session 2015-16. The committee considered the Government's response to the Report and issued this document with the government's response as an Appendix.
The Intelligence and Security Committee reported to the Prime Minister in December 2016 but states that - "In accordance with standard practice under the Justice and Security Act 2013, the Report will now be subject to a redactions process to prepare
it for publication. The Committee expects that this process will be
completed in the New Year."
1. Charter of the United Nations
2. Chatham House
3. Leiden Policy Recommendations
4. Sir Daniel Bethlehem QC (Legal Adviser to the Foreign and Commonwealth Office May 2006 to May 2011) - Principles
relevant to the scope of a State's right of self-defence against an
imminent or actual armed attack by non-State actors
5. Speech by Brian J Egan - April 2016 - International Law and the use of force against ISIL