Chapter 8 looks at the general rules which apply to the means and methods of warfare, and what kinds of weapons have been prohibited or restricted under IHL. The general principles governing how warfare is conducted are explained – the prohibitions on causing unnecessary suffering and superfluous injury, and on indiscriminate means and methods. The chapter examines a number of particular weapons, such as dum-dum bullets, mines and booby-traps, weapons that leave non-detectable fragments in the human body, incendiary weapons, blinding laser weapons, cluster munitions and chemical and biological weapons. Chapter 8 also looks at the problem of explosive remnants of war being left in the conflict zone, as well as a number of means and methods which have been the focus of much attention but whose legality is highly contested, including nuclear weapons, white phosphorus, depleted uranium munitions, cyberwarfare, drone warfare and targeted killings. The chapter also explains prohibited methods of warfare such as ordering ‘no quarter’, perfidy, siege and pillage, along with the particular rules relating to belligerent reprisals, mercenaries, espionage and autonomous weapons.

Chapter 4 examines reconnaissance operations. Reconnaissance seems, prima facia, to be the least problematic of the special operations mission set from an ethical perspective. Intelligence gathering is universally acknowledged as a legitimate operation in war and peace. Done well and according to plan, reconnaissance missions involve no loss of life and often provide information that enables more discriminate targeting. But reconnaissance operations conducted by SOF, ’special reconnaissance (SR)’, often involve peculiar moral risks. SR missions are typically carried out over a long duration, deep in unfriendly territory, and with limited or tenuous means of support available. If a SOF reconnaissance team is compromised, the consequences are particularly pernicious. Given that compromise could result in mission failure, national embarrassment, imprisonment, or death, are there moral limits to what SOF teams can do to prevent detection? For example, are SR teams ever justified in killing, detaining, or otherwise harming non-combatants to avoid discovery? Wearing camouflage is generally accepted as ethically unproblematic, but what about the practice of ’hiding in plain sight’ by falsifying personal identification, donning local garb, or even dressing in the uniform or distinctive clothing of the enemy? At what point does concealment of identity become perfidy?

Section E seeks to show how the law on the conduct of hostilities that would apply in relation to the use of conventional weapons also applies in respect of nuclear weapon operations. The Rules and Commentaries deal with persons participating in the hostilities, who are distinguished from protected civilians, and with specific issues of naval and air warfare. The Rules and Commentaries on nuclear targeting address the notion of ‘attack’, the principle of distinction, prohibited nuclear attacks, the definition of military objectives, proportionality and active and passive precautions. As to methods of nuclear warfare, the Section addresses perfidy and ruses, the improper use of protective indicators and emblems, as well as the concept of zones. The Section further includes Rules and Commentaries on persons and objects entitled to specific protection and on the protection of the natural environment in times of armed conflict.

Chapter 11 is a brief chapter on seldom encountered legal issues: ruses and perfidy. Acts that invite an enemy’s confidence that he is entitled to protection under the rules of LOAC, with an intent to betray that confidence, is the crime of perfidy. It has been a codified war crime since 1907, though seldom prosecuted. False flags of truce, informing an opponent that the war is over so you can come on out, are perfidy, as is fighting in the enemy’s uniform. Feigning being wounded, however, is not perfidy, because it does not invite an enemy’s confidence. Examples in recent years are related: in Columbia against the FARC, in the Falklands against the British. Ruses, on the other hand, are lawful: deceit employed in the interest of military operations for the purpose of misleading the enemy. They do not invite the confidence of the enemy with respect to the protection of LOAC. Dummy artillery pieces, inflatable “tanks,” mock operations by nonexistent troops, all lawful.