Our comprehension of the legal means and methods by which military forces are employed, controlled and — where considered necessary — immunised, is incomplete. Some questions are — in a jurisprudential sense — well settled, or at least evolving along a logical, comprehensible, and generally linear course. Thus the scope of the defence power under the Australian Constitution has, on the whole, been relatively consistently interpreted over time as an elastic power — expanding in time of large-scale conflict, contracting in time of profound peace, variably waxing and waning between these two poles in situations of uncertainty less than war but short of settled peace. There have certainly been some new developments in understanding the scope of the power — such as the High Court of Australia’s decision in Thomas v Mowbray (relating to the constitutional validity of the federal control order regime). In this case the majority held that components of the defence power are also exercisable through non-military organs such as the police. But on the whole, our understanding of the power has developed along conceptually and chronologically coherent and logical lines. Similarly, there is no question in the Australian context that this evolution has also been more generally coherent in terms of its interaction with related constitutional questions. Thus Thomas v Mowbray is, in many ways, a belated cross-referral allowing police and intelligence agencies to access authority under the defence power. This merely reflects and accompanies the long established principle that the military forces can likewise be used for law enforcement purposes — as confirmed in Li Chia Hsing v Rankin. It is perhaps justified to say that were we to apply a jus ad bellum / jus in bello approach (law of armed conflict based and thus formally inapplicable, but nevertheless useful) to the problem, the jus ad bellum issues — the when and why of use of military forces in law enforcement operations — are relatively settled, or at least evolving coherently and consistently with their history and precedent.

A growing number of incidents—particularly since 2009—highlight the South China Sea (SCS) as the preeminent venue for the People's Republic of China (PRC) maritime gray zone operations. “Gray zone operations” are, in essence, operations that are designed to exploit or create legal (and other) uncertainties for a military or strategic advantage. A prominent example is the way that China has used the so-called nine(ten)-dash line without fully explaining the legal basis for it. There are other examples, as well. China has deliberately cultivated uncertainty about the sovereign status of maritime militia vessels—and thus about whether and how the conduct of these vessels might be directly attributable to the PRC. It has harassed U.S. survey vessels seventy-five nautical miles (nm) south of Hainan Island in an effort to disrupt military survey operations that it claims are impermissible and has sunk a Philippine fishing vessel at Reed Bank in an effort to enforce Chinese claims to exclusive fisheries rights in this area. It has also asserted claims and enforcement rights in zones that clearly belong to other states—including actions against Indonesian fishing vessels in seas in the vicinity of the Natuna Islands, which are part of the Indonesian Exclusive Economic Zone (EEZ) (and Continental Shelf). And it has conducted operations on the basis of inapplicable maritime zone rights, such as by asserting a territorial sea and thus the right to control innocent passage around low-tide elevations with artificial installations built upon them—such as with Mischief Reef. The list goes on.

Cyberspace is now acknowledged not only as the newest domain of warfare, but also as a space vital to economic, educational and cultural development for all States. This thin consensus ignores the fundamental fact that the backbone of cyber infrastructure—submarine telecommunication cables—is not (for the large part) located within sovereign territorial jurisdiction. The radically increased reliance of States upon submarine data cables emphasises their vulnerability to damage by malicious acts, accidents, or natural phenomena. Faced with these problems, legal analysis has tended to identify gaps or deficiencies in the law, and propose the creation of new legal instruments. The contribution of this article is twofold. First, it expands the frame of analysis to include deliberate damage to cables not only in peacetime but under the law of armed conflict. Second, rather than treating the legal framework as inherently deficient, it considers the extent to which existing rules and principles can be progressively developed, interpreted, or creatively applied to close perceived gaps. This article surveys the existing law specific to the protection of submarine cables and assesses how general principles of the law of the sea, State responsibility, the law on the use of force, and the law of armed conflict apply to this problem. It thus considers in turn the applicable ‘law of peace’, the jus ad bellum and the jus in bello.

The ongoing development of diverse maritime autonomous vehicles for varied ocean activities—ranging from scientific research, security surveillance, transportation of goods, military purposes and commission of crimes—is prompting greater consideration of how existing legal frameworks accommodate these vehicles. This article brings together the core legal issues, as well as current developments in relation to commercial shipping, the law of naval warfare, and maritime security. This article captures how these issues are now being addressed and what other legal questions will likely emerge as the newest technology impacts on one of the oldest bodies of international law.