Since the adoption of the UN Charter international law is not framed in terms of "act of war", but rather in terms of "use of force". Article 2(4) of the Charter prohibits the threat or use of force that threatens the territorial integrity or political independence of any state. However the Charter also recognises that a state has a right to use force to defend itself against an armed attack or imminent armed attack. Actions that fall short of an armed attack could still constitute an unlawful intervention in the domestic affairs of the UK, prohibited by both Article 2(7) of the UN Charter and customary international law. Any assessment would need to be made on a case-by-case basis, taking into account all of the facts.