As reported by David Crowe in the Sydney Morning Herald, Ukraine’s Foreign Minister, Dmytro Kuleba, has recently called on individuals, from other countries, to join the fight against Russia’s invasion.

“Foreigners willing to defend Ukraine and world order as part of the International Legion of Territorial Defence of Ukraine, I invite you to contact foreign diplomatic missions of Ukraine”, he said on Sunday night.

It is important to note that it is illegal for Australians to take up this call. As things stand, Australians commit a criminal office if they fight for any formation other than properly constituted national armed forces. This prohibition was introduced to deter and punish Australians hoping to fight in the ranks of ISIS. However, it applies far more generally. As such, it proscribes an age-old practice of individuals engaging in warfare in support of causes they wish to champion. Unlike mercenaries (who will fight for whichever side will pay them the better price), there have been people, throughout history, willing to risk their lives and limbs for idealistic reasons.

More recent examples include those who joined the International Brigade to fight Fascist forces in Spain during the early part of the Twentieth Century, those who joined the Kurds to oppose ISIS, in recent years, and also those who fought with and for ISIS in order to establish a Caliphate in the Middle East.

It should be noted that the choices mentioned above are not morally equivalent – even though the underlying motivation is, essentially, the same. Those who opposed Fascism in the 1930s did not employ terrorism as a principal tactic. ISIS did – unrestrained by any of the ethical limitations arising out of the Just war tradition.

That tradition was developed to deal with forms of war which took place in real time and across real battlespaces where combatants and non-combatants could be killed by a direct encounter with a lethal weapon or its effects.

In recent days, this discussion has taken on a new character as volunteer ‘hacktivists’ have taken up virtual arms, on Ukraine’s behalf, in a cyber-war against Russian forces. Once again, there are non-Ukrainian nationals engaged in a conflict that pits them against an aggressor – not for financial reward, not for reasons of self-preservation but simply because they feel compelled to defend an ideal. Of course, there are bound to be some amongst their ranks who are just in it for the mischief. However, I think most will be sincere in their conviction that they are doing some good.

That said, there is some truth to the old adage that ‘the road to hell is paved with good intentions’. It is not enough to be realising a noble purpose. One also needs to employ legitimate means. It is this thought that lies behind the observation, by Canadian philosopher Michael Ignatieff, that the difference between a ‘warrior’ and a ‘barbarian’ lies in ethical restraint.

In an ideal world, those who belong to the profession of arms are trained to apply ethical restraint in their use of force. The allegations levelled against a few members of the SAS, in Afghanistan, indicate that there can be a gap between the ideal and the actual. However, in the vast majority of cases, Australia’s professional shoulders serve as ‘warriors’ rather than ‘barbarians’.

But what of the ethical restraint required of volunteer cyber-warriors? There are some general observations, as outlined by Dr Matt Beard and I in our publication Ethical By Design: Principles for Good Technology. Our first principle is that ‘CAN does NOT imply OUGHT’. That is, the mere fact that you can do something does not mean that you should!. However, I think that some of the traditional ethical restraints derived from ‘just war theory’ should also apply.

There are three principles of particular importance. First, you need to be satisfied that you are pursuing a just cause. Self-defence and the defence of others who have been attacked without just cause have always been allowed – with one proviso … your own use of force must be directed at securing a peace that is superior to that which would have prevailed if no force had been used.

That accounts for the ends that one might pursue. When it comes to the means, they need to accord with the principles of ‘discrimination’ and proportionality’. The first says that you may only attack a legitimate target (a combatant, military infrastructure, etc.). The second requires you only to use the minimal amount of force needed to achieve one’s legitimate ends.

President Putin’s forces have violated all three principles of just war. He has invaded another nation without just cause. He is targeting non-combatants (innocent women and children) and he is employing weaponry (and threatening an escalation) that is entirely disproportionate.

The fact that he does so does not justify others to do the same.

Volunteer cyber-warriors have to be extremely careful that in their zeal to harm Putin and his armed forces, they do not deliberately (or even inadvertently) harm innocent Russians who have been sucked into one man’s war.

Of course, this means fighting with the equivalent of ‘one arm tied behind the back’. The temptation is to fight ‘fire with fire’ – but that only leads to the loss of one of one’s ‘moral authority’. The hard lessons of history have taught us that this is a potent weapon in itself.

The law might not prevent a cyber-warrior from fighting on the side of Ukraine from a desk somewhere in Australia. However, one should at least pause to consider the ethical dimension of what you propose to do and how you propose to go about it.

There can be honour in being a cyber-warrior. There is none in being a cyber-barbarian.