Mercenaries are not protected by the Geneva Conventions. When caught in combat, they are to be treated as criminals under common law. Likewise with volunteers or members of any kind of militia. This is not a personal opinion, but a reference to international treaties recognised by the vast majority of the governments in the world, united as members of the United Nations.
When Holland grew rich, and went to war with Spain, which country claimed the right to rule over the 'Low Lands', powerful merchants hired mercenaries in Germany and the UK to lead the troops into battle. These mercenaries dragged behind them a 'political class' of 'entitled' would be rulers, and our present Dutch King is a direct descendant of 'lower nobility' from Germany which saw an opening, and jumped right in. The British King today traces his roots back to Germany as well, and war was their 'business'.
Today Ursula von der Leyen, the unelected head of the EU, is presenting her plans for Europe, and the news today in Holland presented it as her 'Troonrede', the plans laid down by the 'Crown', the unelected official sitting on the 'Throne', and people adore that image subconsciously, even when their brain tells them to reject the concept. Likewise, they will tell you that mercenaries are bad news, since killing, maiming and bombing for money is extremely immoral. Yet they cheer for the mercenaries leading the way in Ukraine, paid for by NATO (NATO-countries), since Ukraine itself is way past being broke, and lost the bulk of it's army in the past six months of fighting, bogged down in trenches and fortifications mauled by Russian artillery.
Russia sticking to international law, and declaring every combattant they come across which cannot be identified as a member of the regular Ukrainian army a terrorist, and hauling their ass into a civil court, where they are tried as criminals, is seen in the west as Russia treating these noble warriors in an 'inhumane' way, in conflict with international law. It isn't.
Holland using mercenaries to protect itself, and its growing wealth, from claims 'Madrid' said it had on these riches, is seen as smart, and a move which sealed the fate of the 'Low Lands' as an 'eye watering' example of liberal policies creating a sovereign nation being the envy of the neighbourhood, which inspired Adam Smith and others to explain why capitalism was the way to go, and how it would trump feudalism, as long as a country managed to curtail its expenses for 'matters of state', and war, to the rational limit of self-defence. At the same time, money spent on mercenaries transferred wealth to countries which had an abundant amount of people trained and ready to fight, seeking 'positions' in armies around the world, under no obligation to serve anyone but the fellow who paid their services.
Today, NATO is the unique employer making use of hired killers at a huge scale. They recruit them, train them, offer them a chance to prove themselves in one of the many wars they created, then they cut them loose, to hire them back through 'Private Military Companies' to do NATO's 'dirty work', like fighting in countries NATO is not at war with, yet.
Now, Holland didn't grow rich because it went to war whenever the opportunity presented itself, but by avoiding war as much as possible, and doing 'trade' and 'manufacturing'. The need to pay for mercenaries was a burden, not a source of income. Smith and the early liberals recognised this, which translated into an 'isolationist' constitution in the US. Those feudal and parasite forces which sold themselves as soldiers were not too happy about that, and sought to exploit differences within the USA to create an opening through the 'Civil War', which made them rich and powerful, regaining wealth lost to the civilised class.
When Eisenhower warned his country about the dangers of the 'Military-Industrial-Complex', what he had in mind was that the US might develop into a feudal state, with wealth not being earned through production and trade, but by becoming the 'Hired Hand' in wars around the globe. A timely warning, which was not just ignored, or misrepresented, but eventually exploited as the 'way to go'. Recognising the need to improve on the sales-pitch by telling the world they would only allowed themselves to be hired for 'Noble Causes'. Such as destroying countries which had no need for their services. It wrecked our moral compass, and created opportunities for cynical people who kept their distance from the actual battlefield, but 'designed' wars.
They thought about excuses, how to overcome resistance, and create events to grow demand for war. They contracted a wide variety of operational people not afraid to do the 'dirty work' in preparation of yet another war. Which, at some stage, generated the demand for Muslim extremists, paid for by oil-producing countries, and armed, trained and provided with strategic plans and 'intel' by NATO. Before NATO created the 'Private Military Companies' to avoid the stench that came with using 'head choppers'. And now we're ready for nuclear Armageddon as the culmination point of this stupid, but still highly profitable concept. Profitable for as long as there is an industry, and trade left to foot the bills. But we are rapidly approaching the end of the line as our efforts are killing the host.
NATO itself won't switch sides that easily, but 'Hired Hands', at the operational level as well as the planning level, will. Let's hope the Russians and China are not as stupid as we are if they manage to bring this to an end, and reboot rent-free 'Industrial Capitalism' as the only possible way forward. I'll never figure out why we allowed ourselves to be trapped like this, wasting away all the accumulated wealth as we mortgaged it to pay for more wars, which left us with a mountain of debt, as the entire 'shithouse goes up in smoke', to paraphrase Jim Morrison, who said he wanted his 'kicks' before that happened. Entire generations followed his lead, ignoring the need to maintain and build, while selling out to the highest bidder who pleased us with promises of unlimited consumption. As mercenaries corrupted by the mercenary-class to keep our head down, and enjoy the party. Not a good choice.