Foreign fighters in Ukraine may get caught in legal crossfire

Ukrainian Territorial Defence Forces fighters stand guard in Independence Square in Kyiv. Picture: AFP

Ukrainian President Volodymyr Zelensky has called for foreign volunteers to join an international brigade to fight Russia’s invasion of Ukraine. Volunteers have been asked to contact Ukrainian embassies. Since 2016 Ukraine’s law has allowed foreign volunteers.

The call is partly symbolic, given that, by recently banning men aged 18 to 60 from leaving the country, Ukraine now has a pool of almost six million potential fighters to draw on who speak Ukrainian and know the country, and many of whom have military experience. Untrained Australians are unlikely to assist, however well-intentioned, or especially if going for more nefarious or adventure-seeking purposes.

Ukraine’s embassy in Australia has indicated that it will consult with Australian authorities. Scott Morrison has warned Australians not to embark on a “suicide mission” and has flagged legal risks of volunteering.

Foreign fighters have participated in conflicts since mediaeval times. Most have tended to be involved in civil wars, with one study finding that 20 per cent of 331 civil conflicts from 1816 to 2005 involved foreign fighters.

Many of these conflicts nonetheless involved national liberation struggles, more akin to international than civil war, or internationalised conflicts involving foreign powers.

Well-known examples include the republican International Brigades in the Spanish civil war (with more than 50,000 volunteers), Jewish volunteers in Palestine in the 1930s and ’40s (more than 5000), and thousands in the Balkan and Chechen wars in the ’90s. Foreigners also joined the mujaheddin in Afghanistan from 1978 onwards.

In recent years attention has been focused on foreign terrorist fighters, such as the 40,000 people from 100 countries who joined Islamic State in Syria and Iraq from 2014, or the 8000 to 10,000 foreign fighters still in Afghanistan last year. UN Security Council resol­utions have required all states to take measures to prevent and suppress the travel of and support for them.

However, foreign fighters routinely serve in government forces in conflicts, too. Often these are dual nationals, such as Australians who fought in British or US armed forces in recent conflicts in Iraq and Afghanistan, or for the Israel Defence Forces in occupied Palestinian territory. Sometimes they are members of Australian armed forces on secondment to allied forces. And sometimes they are freelancers, whether members of the French Foreign Legion or private military contractors working for foreign governments.

Under international law, foreign fighting is prohibited only where it is for the purpose of taking part in terrorist acts. The problem is that Security Council resolutions have not defined terrorist acts, including whether these are limited to attacks on civilians or include any war-fighting by state or non-state armed forces, even if it complies with the law of war.

In addition, under customary international law, states must prevent their territories from being used to prepare for attacks on foreign governments. This includes any recruitment, training or financing of insurgents.

Under international humanitarian law, combatants who are part of state armed forces in international armed conflicts, such as the one between Ukraine and Russia, have immunity from domestic criminal prosecution for lawful acts of war, which ordinarily would constitute peacetime crimes such as murder. This includes immunity from prosecution for terrorism offences under national law.

Under Australian law, federal foreign incursion and recruitment offences do not prohibit Australians from serving in foreign government armed forces (which are not at war with Australia), and criminalise only engaging in hostilities against foreign governments. Australians do not need to be a national of the other country to serve in its armed forces. They also do not need prior permission of the Australian authorities. Certainly where a person is a dual national, the law thus recognises the sovereign right of the foreign state to have its nationals serve in its armed forces.

The armed forces of a foreign government, understood in light of the law of war, arguably include its regular armed forces, but also irregular forces under the state’s overall control.

This could include Ukraine’s foreign legion, as long as Ukraine maintains sufficient control over it. This will be an important question if the Ukrainian military command is progressively degraded by Russian attacks.

For the same reason, coupled with the difficulty of training new recruits under present circumstances, there are real risks that foreign fighters will not be under adequate discipline so as to comply with the laws of war and not commit war crimes. Combatants must, for example, distinguish themselves as fighters and not conceal themselves as civilians.

While service is legal, it is, however, separately an offence to recruit or advertise for the recruitment in Australia of persons to serve in foreign state armed forces. This would include any calls or facilitation by the Ukraine embassy or other actors in Australia, including the publication of advertisements on social media. While these are offences, Ukrainian diplomats nonetheless enjoy diplomatic immunity, which bars their prosecution.

Nonetheless Australia’s terrorism offences potentially could capture volunteers. Terrorism offences include committing acts of violence (including in war) intended to coerce or intimidate any foreign government (including Russia), to advance a political cause (such as defence of Ukraine).

Australian law against terrorism unfortunately does not exempt the activities of armed forces in armed conflict, as is the case under six international counter-terrorism treaties and laws in the EU, Canada and New Zealand. This means fighting for a foreign government is technically terrorism, even if such fighting complies with the law of war.

Prosecutors still could exercise their discretion not to prosecute. But this is problematic. The British Supreme Court has found it is contrary to the rule of law and the separation of powers for the parliament to adopt excessively broad terrorism offences, then leave it to the discretion of prosecutors, as part of the executive, to decide on a case-by-case basis who is a terrorist. The law itself should clearly identify who is acting unlawfully, to avoid politicising prosecutorial decisions and resulting in selective punishment.

Australian soldiers cannot be prosecuted as terrorists for war-fighting because they enjoy a defence of “lawful excuse” under Australian law, since they are authorised to fight.

But this is not the case for Australians serving in foreign armed forces who may be authorised under foreign but not Australian law. It still would violate international humanitarian law to prosecute, since combatants have immunity from national criminal prosecution, placing Australia at risk of violating its international obligations.

The Australian foreign minister has a power to declare areas in foreign countries off-limits to Australians, with criminal penalties, unless a person has a legitimate reason to be there. The power was used in Raqqa, Syria, and Mosul, Iraq, to counter Australians joining ISIS there. However, this power first requires the existence of a listed terrorist organisation and is designed to stop fighting for that group, and service in government forces is exempt. And there is no group listed in Ukraine. Even if it is arguable that pro-Russian separatist forces are terrorist, declared areas would apply only to those areas, namely eastern Ukraine, not the whole country.

In principle, Australians could also join the Russian armed forces to serve in Ukraine and would not be captured by the foreign incursions and recruitment offences.

However, Australia has military sanctions on Russia, which include providing any military service to Russia. This could be interpreted to cover military service (although it is unclear), in which case breaches of sanctions attract criminal penalties.

Volunteering to resist aggression in Ukraine may be a noble cause, especially when foreign governments are not willing to contribute troops. But even if it is lawful for Australians to join, there are serious risks that they may not be under responsible military command, and end up violating the laws of war.

Ben Saul is Challis chair of international law at the University of Sydney, and an associate fellow of Chatham House, London, and of the International Centre for Counter-terrorism, The Hague.