This book, a tribute to the work and research of Professor Terry D. Gill, offers an insightful view into the field of the International Law of Military Operations (ILMO). ILMO is a distinct sub-discipline within public international law and domestic public law, which covers all domains of military operations: land, sea, air, space and cyberspace. As such, it includes a wide range of elements of other branches of public international law, including international humanitarian law, human rights law, the law on the use of force, the law of the sea, the law of State responsibility, arms control law and the law of international organisations. Importantly, as a hybrid field of law, ILMO covers the legal basis for military deployment both nationally and internationally, as well as the subsequent international legal regimes applicable to the forces (once deployed) and the domestic administrative and constitutional issues related to the relevant forces.

From these components, the central notion of this edited volume is derived: control. Control plays a role in military operations in various legal and factual ways. The legal notion of control is considered in several contributions dealing, inter alia, with control in relation to restraints in the decision to deploy and the legal basis for doing so, be it in armed conflict, peace-support operations, or in domestic circumstances; the legal requirement to be in effective control should a situation of belligerent occupation arise; and the relevance of control – or the lack thereof – when attributing responsibility and accountability, e.g. with regard to immunities, privileges, State responsibility, criminal accountability – both individual and command-based.

Additionally, various forms of factual control are considered: control over the type and/or scale of force used in operations; control as a mechanism to constrain or escalate force; control in operational procedures such as targeting, where these procedures merge with the law, e.g. the law of armed conflict; and the ability to exercise control via soft law or rules of engagement, not only to restrain force, but also to ensure the effectiveness of the force used. Moreover, as a result of such factual control, or control in a physical sense, legal consequences arise. Having control over the armed forces themselves, or over detainees or migrants (at sea), over terrain, airspace or sea, has legal implications, for instance the application of international human rights to extraterritorial operations, or the application of the law of occupation to the acts of the armed forces.

Furthermore, the book contains several discussions on arms control law, and aspects of control relevant to the deployment or development of weapons and weapon systems, such as control over the admissibility and procurement of weapons, especially new types such as semi-autonomous or unmanned weapon systems.

The editors of the book are all affiliated to the Faculty of Military Sciences (War Studies) of the Netherlands Defence Academy and/or the Law Faculty of the University of Amsterdam.

Specific to this book:

• The first volume within the field of ILMO on the central theme of control, with contributions from many of the major branches of international law.
  
  The first volume, as far as we know, within the field of international (military) law that takes the notion of ‘control’ as its central theme.
  
  The contributors are experts, or in some cases the experts, on the issue of their chapter and are therefore particularly well placed to approach the central theme of the book from their own expertise.
  
  The contributions are written by academics and/or practitioners so hold relevance for both academic researchers and those working in the field.
  
  A Liber Amicorum for one of the leading contemporary scholars in the fields of ILMO, IHL, and ius ad bellum.