(KYIV, Ukraine) — When Andy Huynh watched the news of Russia’s invasion of Ukraine in February, he started losing sleep. All he could think about was the struggle of the Ukrainian people against an aggressor he felt was violating their sovereignty and opening the world up to a third World War.

“All my personal problems didn’t feel important anymore … It felt wrong just to sit back and do nothing,” he said. “I had to go.”

The Alabama man was not alone. Two days after the invasion, Ukraine’s President Volodymyr Zelenskyy called for “friends of Ukraine, freedom and democracy” to serve as volunteers in the Ukrainian military. More than 20,000 volunteers from 52 countries responded, many of whom had served in the U.S. Army, British Army, and, like Huynh, the U.S. Marine Corps, according to Ukrainian officials.

Their experience is credited by Zelenskyy for bolstering the war effort for Ukraine, especially since NATO countries have rejected sending ground troops in fears of starting their own conflict with Russia. Russian President Vladimir Putin announced in March that 16,000 volunteers from the Middle East would be joining his country’s fight.

Tanya Mehra, a senior research fellow at the International Centre for Counterterrorism at The Hague, said the mobilization of foreign fighters on battlefields dates to 1816 and they have played prominent roles in conflicts in Afghanistan, Bosnia, Chechnya and Somalia since the 1980s.

The evolution of foreign-born fighters has created distinct classes of fighters, from mercenaries who join conflicts primarily for financial gain, Mehra said, and others who are driven by ideological reasons. Mercenaries, she said, who are outsourced contractors for small governments, tend to be associated to “increases in violence and higher civilian casualties,” which can prolong the conflict, whereas foreign fighters become part of the state military, which makes them “accountable for the acts they have committed.”

Many of those foreign fighters serving in Ukraine tend to be older than your average soldier, and in a stage in their lives where they felt they could help through their years of experience.

John Harding, 59, joined the Ukrainian military in 2018, when the country was fighting Russian-backed separatists. As a professional combat medic who served in Syria, the British-born Harding put his experience to use on the battlefield. But he also found he was in demand as a trainer for other medics who had no idea how to apply first aid in a hostile combat environment

“Medics are notorious for getting themselves killed,” Harding said. “You may know how to apply a torniquet, but you also need to know how to apply a tourniquet while watching out for snipers.”

One American, who did not want to use his name because he is still fighting in Ukraine, said he joined the Ukrainian military in April because he felt “it is important for the world to stand up with the Ukrainians and resist aggression.” Having grown up in a military family and a U.S. Air Force veteran himself, the man took leave of his job in IT while living in central Europe to join the fight.

Today, he uses his background in engineering systems, cybersecurity and computer networks to operate drones in anti-tank and stinger missions. He said his squad was responsible for taking down a Mil Mi-28 Russian helicopter on July 18. The man said his homemade bombs and grenades are constructed using Coke cans and some of the 60 kilograms of TNT captured during an offensive in September. They take flight via off-the-shelf commercial drones.

The man said that the number of foreign fighters he encounters, the majority of whom were from the U.S., has decreased since the spring. The intensity of the fighting weeded away what he called the “TikTok warriors” who were not prepared for the danger, or length, of the missions. He remains fighting after seven months because of ideological reasons, but also because of the survivor’s guilt he felt when two men from his squad — Huynh and Alex Drueke, also from Alabama — were captured on June 9 following a firefight.

“I felt I lost my two brothers. They followed me to this unit. I felt very guilty,” he said. “Part of the reason I stayed this long is because of them.”

Huynh and Drueke, a U.S. Army veteran, spent 105 days in captivity, including a month in a Russian “black site,” where they endured daily torture. In late September they were released, along with eight other foreign-born volunteer fighters from England and Canada and more than 200 Ukrainian soldiers.

Harding was among those men released. He met Huynh and Drueke in a prison cell after having been captured in May when a Ukrainian unit he was with in Mariupol was forced to surrender. The torture he suffered has led to a diagnosis of permanent neurological damage to his hands, along with broken ribs and damage to his sternum. One aftereffect is “more psychological”: “I have mood swings which I don’t have control of,” he said.

He now lives close to family in Luton, a town in the southeast of England. The results of ongoing medical treatment will determine his ability to work.

“Would I do it again? Knowing what I know, probably not. Would I do it again if I didn’t know? Yes, I would,” he said. “The only thing I would have done different is I wouldn’t have surrendered. I would have fought to the very last round.”

Like Harding, Drueke and Hyunh also say they have no regrets. Back home in Alabama, they are adjusting to their former lives. Hyunh is engaged and will marry soon, while Drueke is contemplating his next career move. They have bonded, not just with one another, but with Harding and the other men in their unit who are either still in Ukraine or returned home. One day they hope to reunite, either in the U.S. or in England — or even Ukraine itself to help rebuild.

“Honestly, Ukraine has really surprised the world. We did not expect them to be that feisty, that strong, that determined,” said Drueke. “They are amazing people.”

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(SHARM EL-SHEIKH, Egypt) — Negotiators from around the world are gathering in Egypt this week for this year’s biggest international climate summit, called COP27.

The United Nations recently warned the world is far from its goal of limiting global warming to 1.5 degrees Celsius warmer than before the industrial revolution, the goal set by the Paris Climate Agreement.

Current policies would lead to 2.8 degrees Celsius of warming by the end of the century, according to the UN Emissions Gap Report, meaning countries need to reduce emissions significantly more to keep the Paris Agreement goal within reach. If every country and private company meets its climate goals, warming could be limited to 1.8 or 1.9 degrees Celsius, but there are still questions about whether enough is being done to make those goals a reality.

“Every degree does matter, 1.5 degrees is the scientific goal of a climate [that] remains stable. After that, things become exponentially more difficult,” Ani Dasgupta, president and CEO of the World Resources Institute, told ABC News.

“So it’s true, that argument the world won’t stop in 2030 if you did or didn’t reach 1.5, but it becomes that much more difficult and that much more risky for human life. So our goal is to be within that.”

Dasgupta said the pressure is more on the largest emitters like the US, Europe, China, and India to be more ambitious because they contribute far more greenhouse gas emissions.

President Joe Biden is scheduled to attend the summit in Egypt and is expected to tout his domestic policy wins on climate this year, including the infrastructure bill and Inflation Reduction Act which included historic amounts of money for clean energy and climate programs.

The meeting takes place with the backdrop of several climate-driven disasters this year, including the devastating flooding in Pakistan and severe drought and famine conditions in East Africa. The world is about 1.2 degrees Celsius higher than the pre-industrial average and experts said this year proves most countries are not prepared for even that amount of warming.

Dasgupta said many of these crises are not just weather disasters but they also bring huge economic impacts, which is one reason there will be so much focus on providing more finance for countries feeling the impacts of climate change.

“This particular year that we are ending, or almost ending, has been devastating in climate-related weather disasters, like a banner year,” he said.

“That is the context of what a 1.2-degree world looks like … so we’ve talked about 1.1, 1.2 [degrees] it always seemed like something you have to imagine. Literally this year you don’t have to imagine, you could just read the newspaper or watch television to see.”

Countries already experiencing dangerous and expensive impacts of climate change, like flooding or food and water insecurity, are expected to pressure wealthier countries like the U.S. to provide more funding to help them adapt or relocate.

This idea known as “loss and damage” financing suggests that countries that contributed emissions that have led to global warming should do more to help communities who contributed less to the problem, but are already feeling the impacts. Special Presidential Envoy for Climate John Kerry said the U.S. is committed to “engaging constructively” to find a way to address the issue but the U.S. has not yet supported a proposal for a new fund for loss and damage.

Kerry, who will represent the US at the summit, says he still believes the world can meet its climate goals but there are still big political and financial challenges to getting it done. Kerry said the transition underway now is bigger than the industrial revolution and will result in a cleaner and more secure energy system.

“While many of us are chagrined it has taken so long for us to get to a place where more and more people are accepting what’s happening, we are there. And the only way to be able to organize ourselves and get the job done when you have 200 or so nations that are involved in this is to come together somewhere and work at it,” he said at a press briefing this week.

The COP27 begins in Sharm el-Sheikh, Egypt on Nov. 6 and is scheduled to conclude Nov. 18.

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