A/66/152 (b) The use of force in self-defence must be limited to what is necessary to address an imminent or actual armed attack and must be proportionate to the threat that is faced; (c) States are required to take all necessary measures to ensure that their territories are not used by other States or non-State actors for purposes of armed activities, including planning, threatening, perpetrating or providing material support for armed attacks against other States and their interests. Jus in bello. The law of armed conflict set forth the rules, known as jus in bello, that apply to the conduct of armed conflict, including the use of information technology tools in the context of an armed conflict. In particular, the following key principles of the law of armed conflict would play an important role in judging the legality of cyberattacks during an armed conflict: (a) The principle of distinction requires attacks to be limited to legitimate military objectives and that civilian objects shall not be the object of attack; (b) The prohibition on indiscriminate attacks includes a prohibition on attacks that employ a means or method of warfare that cannot be reasonably directed at a specific military objective; (c) The principle of proportionality prohibits attacks that may be expected to cause incidental loss to civilian life, injury to civilians, or damage to civilian objects, which would be excessive in relation to the concrete and direct military advantage anticipated. These principles prohibit attacks on purely civilian infrastructure, the disruption or destruction of which would produce no meaningful military advantage. In addition, the potential for collateral damage would have to be assessed before attacking a military target. In other words, targeting analysis would have to be conducted for information technology attacks just as it traditionally has been conducted for attacks using kinetic (conventional and strategic) weapons. While the principles above are well-established and apply in the context of cyberspace, it is also true that interpreting these bodies of law in the context of activities in cyberspace can present new and unique challenges that will require consultation and cooperation among nations. This is not unusual. When new technologies are developed, they often present challenges for the application of existing bodies of law. C. The use of proxies The use of proxies to conduct disruptive operations is an example of an area where the unique attributes of information and communications technologies present new challenges for States. Acting through proxies significantly increases States’ ability to engage in attacks with plausible deniability. While existing international law has provisions governing the use of mercenaries, the use of proxies in cyberspace raises new and significant issues with wide-ranging implications. States will need to work together to develop effective solutions to this problem. D. Responsibility to allow free flow of information The rights to freedom of expression and the free flow of information are embodied in the Universal Declaration of Human Rights and the International 11-41691 19