II. The Grey Zone Is Defined by the Defender

Over the course of recent years, it has become common to hear the term ‘grey-zone strategy’ invoked to conceptualise the ways in which a range of state competitors are pursuing revisionist goals. Per this understanding, Western adversaries such as Russia, China and Iran have become adept at using a range of tools short of open warfare to challenge the status quo, leaving Western policymakers scrambling to come up with appropriate and proportionate responses. Similarly, the US and its allies have their own grey-zone tools, including support for colour revolutions, financial sanctions and cyber attacks. Thus, for example, the US Joint Chiefs of Staff envision an operating environment defined by sub-threshold activity and attendant ambiguity. Nor is this an exclusively American view: the UK’s Integrated Operating Concept notes that ‘our adversaries use an array of capabilities including their militaries below the threshold of war and in ways that challenge our political and legal norms’. Similarly, France’s 2017 national security strategy notes the challenge posed by legally ambiguous forms of aggression in the information space: ‘Ambiguous postures and covert aggression are also becoming more common, with certain states making an increasing use of a wide variety of proxies.’