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armed attack and in respect of acts of self-defence that are carried out by cyber means.
Thus, if a cyber activity – alone or in combination with a physical operation – results
in, or presents an imminent threat of, damage equivalent to a traditional armed attack,
then the inherent right to self-defence is engaged. Any use of force in self-defence
must be necessary for the State to defend itself against the actual or imminent armed
attack, and be a proportionate response in scope, scale and duration. Any reliance on
Article 51 must be reported directly to the UN Security Council.
The rapidity of cyber activities, as well as their potentially concealed and/or
indiscriminate character, raises new challenges for the application of established
principles. These challenges have been noted by Australia in explaining its position
on imminence and the right of self-defence in the context of national security threats
that have evolved as a result of technological advances. For example, in a speech to
the University of Queensland in 2017, then Attorney-General, Senator the Hon.
George Brandis QC, explained that:
‘[A] state may act in anticipatory self-defence against an armed attack when the
attacker is clearly committed to launching an armed attack, in circumstances
where the victim will lose its last opportunity to effectively defend itself unless
it acts. This standard reflects the nature of contemporary threats, as well as the
means of attack that hostile parties might deploy. Consider, for example, a
threatened armed attack in the form of an offensive cyber operation, …which
could cause large-scale loss of human life and damage to critical infrastructure.
Such an attack might be launched in a split-second. Is it seriously to be
suggested that a state has no right to take action before that split-second?’
2.
International humanitarian law (jus in bello) and international human rights law
International humanitarian law (IHL) (including the principles of humanity,
necessity, proportionality and distinction) applies to cyber activities within an armed
conflict.
Australia considers that a cyber activity may constitute an ‘attack’ against an
adversary under IHL if it rises to the same threshold as that of a kinetic ‘attack’ (or
act of violence). The rules governing such attacks during armed conflict will apply to
those kinds of cyber activities. Accordingly, it will be necessary to assess whether the
cyber activity is sufficiently connected to hostilities and results in the reasonably
foreseeable death or injury to individuals or damage and destruction to objects. IHL
also provides rules that apply to cyber activities in an armed conflict that do not
constitute or rise to the level of an ‘attack’, including the general protections afforded
to the civilian population and individual civilians against dangers arising from
military operations.
In accordance with the IHL principle of military necessity, a combatant is
justified in using measures, not forbidden by international law, which are
indispensable for securing complete submission of an enemy at the soonest moment.
The principle cannot be used to justify actions prohibited by law, as the means to
achieve victory are not unlimited.
The IHL principle of distinction seeks to ensure that only legitimate military
objectives are attacked. Distinction has two components. The first, relating to
personnel, seeks to maintain the distinction between combatants (who may be
attacked), and civilians or non-combatants (including protected persons). The second
component distinguishes between objects which are targetable as legitimate military
objectives, and civilian and protected objects.
The IHL principle of proportionality prohibits the launching of an attack which
may be expected to cause incidental loss of civilian life, injury to civilians, damage
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