By Annabelle Timsit, Adam Taylor and Amy Cheng
The government of Ukraine is asking foreign citizens to help fight its war. And some are heeding the call, despite immense personal risk and uncertain legal grounds.
On Tuesday, Ukraine temporarily lifted visa requirements for foreign volunteers who wish to enter the country and join the fight against Russian forces. The move came after Ukrainian President Volodymyr Zelensky created the International Legion of Territorial Defense over the weekend and called on volunteers to "join the defence of Ukraine, Europe and the world".
Foreign Minister Dmytro Kuleba wrote on Twitter that anyone interested in participating should contact Ukraine's diplomatic missions in their respective countries.
"Together we defeated Hitler, and we will defeat Putin, too," Kuleba said on Sunday.
Foreign citizens have been fighting in Ukraine since 2014, when Russia-backed separatists seized parts of the Donbass region.
But experts who track foreign fighters say this is a step far beyond that in ambition. Ukrainian embassies are openly involved in the recruitment of fighters, while Western governments have offered support for those who wish to join the Ukrainian side.
"It's potentially way, way bigger than it was in 2014," said Kacper Rekawek, a postdoctoral fellow at the Center for Research at Extremism at the University of Oslo who has studied foreign fighters in Ukraine.
Rekawek put the number of foreigners involved in that earlier fighting at around 1 000.
The risks are extraordinary. Ukrainian cities have weathered cycles of intense shelling, and talks between Kyiv and Moscow did not produce any breakthroughs.
At least 11 people were killed in the eastern city of Kharkiv on Monday, and more were injured, Ukrainian officials said. Suspected cluster munitions struck buildings in residential parts of the city.
"It's very dangerous for people to travel (to Ukraine) at the moment," said Ed Arnold, a research fellow for European security at the London-based Royal United Services Institute think tank. Fighting in a war is "not as easy as picking up a weapon and just going to fight," he said.
Arnold, who served as an infantry officer in the British army, said it might be safer for those with military training. However, "if you have no military training, it's a very silly idea", he added.
Most of the foreign fighters in Ukraine are from other post-Soviet states like Georgia and Belarus.
Mamuka Mamulashvili, the commander of a group called the Georgian Legion fighting in Ukraine, said he was co-ordinating with the government in Kyi to help receive international fighters. He currently had more than 200 men under his command, he said.
"They're mostly Georgian, but there are different nationalities," Mamulashvili said, adding that among his unit were people from Britain, the United States, Albania and India.
"It's a lot of different guys, and we are waiting for more," Mamulashvili said.
The Georgian Legion was the only international group in Ukraine. It was now the Georgian fighters' responsibility to create a "bigger, lets say, brigade", Mamulashvili said.
If the numbers grow as hoped, the Ukrainian war could mark the greatest recruitment of international fighters in Europe since the Spanish Civil War.
At least 50 000 people joined International Brigades in support of the Soviet-backed Republican cause in Spain between 1936 and 1938. Though the Republicans were ultimately defeated by Nazi-aligned Nationalist forces, they became an international cause celebre for the left, inspiring writing by George Orwell and Ernest Hemingway.
Lisa Kirschenbaum, a professor of history at West Chester University, said that while there were no similar ideological appeals made by Ukraine, there were "clear parallels" between the recruitment of foreigners during the Spanish war and the recruitment in Ukraine, even down to the language used.
"The framing of the call for volunteers, equating the war against Hitler and the war against Putin, suggests a more symbolic role, or, if you like, propaganda purpose," Kirschenbaum said. "The arrival of foreign volunteers effectively marks Ukraine's cause as the cause of the 'civilised' world."
In remarks and votes, officials in various European nations have allowed or appeared to encourage their nationals to fight on behalf of Ukraine.
On Monday, lawmakers in Latvia voted unanimously to allow Latvian citizens to fight in Ukraine, according to Reuters.
In Denmark, Prime Minister Mette Frederiksen said on Sunday that "there is nothing at first sight that would legally prevent someone from going to Ukraine to participate in the conflict, on the Ukrainian side".
In Canada, Foreign Minister Mélanie Joly said on Sunday that while the government had warned that travelling to Ukraine was dangerous, joining the fight was an individual choice that Canadians could make for themselves.
"We understand that people of Ukrainian descent want to support their fellow Ukrainians and also that there is a desire to defend the motherland, and in that sense it is their own individual decision," Joly said.
British Foreign Secretary Liz Truss told the BBC on Sunday that she supported people in Britain who might want to travel to Ukraine to join the fight, adding that Ukrainians were fighting for freedom, "not just for Ukraine but for the whole of Europe".
However, on Monday, British Defence Secretary Ben Wallace was asked on Sky News about Truss's comments and said there were "better ways" for civilians to "contribute to the security of Ukraine".
While he agreed with Truss that Ukraine was defending democracy, travelling to Ukraine could be dangerous for people with no military background, Wallace said.
"If you're keen to help and you're a United Kingdom citizen, come and join our armed forces," he said.
Other countries have been more cautious. Ukrainian authorities said on Monday that the Georgian government was blocking a charter flight from Tbilisi to Poland that contained foreign citizens ready to fight.
Georgian Legion commander Mamulashvili said that about 500 Georgians had been expected to join him in Ukraine before the flight was blocked.
"I would say the Georgian government is totally pro-Russian and supporting the Russian occupation of Ukraine," Mamulashvili added, though Georgia has itself been invaded by Russia and condemned the 2014 annexation of Crimea.
Some countries also have laws that could prohibit citizens from fighting in Ukraine. In the United Kingdom, a law from 1870 bans fighting alongside any country at war with a country that is at peace with Britain. However, the law hasn't been used for a century, including during the Spanish Civil War.
Most Western focus on foreign fighters in recent years has been on citizens who join extremist groups, such as the Islamic State in Syria. Though the British government did try to prosecute some citizens who fought with Kurdish militias in northern Syria, the cases fell apart due to the difficulty in establishing if these were terrorist acts.
"There is a gray area," said Rekawek, the researcher from the University of Oslo. "We're in this fantastic world in a sense in which being a foreign terrorist fighter is illegal everywhere. But being a foreign fighter? Oh, that's a slightly different kettle of fish."
Aaron Zelin, a fellow at the Washington Institute for Near East Policy who tracked the role of foreign citizens during the Syrian war, said that the context of Ukraine made it significantly different for Western governments.
"The foreigners who are volunteering to fight on behalf of Ukraine are unlikely to return home and then have an ideology that makes them want to conduct some type of terrorist attack in the heart of London or Paris or Brussels," Zelin said.
But war is unpredictable.
"There is obviously a danger that among the range of people who might travel to fight for Ukraine would be some who are looking for excitement or simply enjoy fighting," said Anthony Dworkin, a senior policy fellow at the European Council on Foreign Relations.
"Obviously, it's understandable why Ukraine would welcome anyone who is ready to fight, but countries should be very cautious about encouraging it," Dworkin added.