The city of Babylon became so infamous for being this trope that in Revelation it is described as a "whore". Of course, there's a reason why Babylon existed for 6,000 years. They realized a simple truth early on: it doesn't actually matter who the king is if you're the one holding the purse strings. Although to be fair, this is also the reason that the Arab jihad leveled the city (rather than occupying it, like they did with most of the great ancient cities they conquered).
The Macedonians, Thebans, and the Branchidae priesthood during the Persian Wars in the 4th Century BCE. The Macedonians got used as cannon fodder at Thermopylae, and swore revenge on the Persians as a result: leading to Alexander the Great's conquests a century later. Ironically, it then fell to Alexander as the representative of the Hellenic League to exact revenge on the Branchidae (who had been hiding out with the Persians). Alexander also wiped out Thebes for unrelated reasons (mainly for general douchebaggery and specifically for revolting against his government).
Caria, a state which was Greek in cultural heritage but quite loyal to the Persian Empire: loyal enough to fight Alexander when he arrived, the only one of the few culturally Greek city-states to do so. The stereotypes listed on this trope were often slapped onto Caria by the Romans (of all people). Of course, almost none of that was actually true. We know this because of Herodotus being from Halicarnassus, Caria's capital and largest city.
Early modern
Skilled diplomacy with regional powers was often the main factor behind the conquests of the Spanish and Portuguese Empires, at least as much as extemporaneous factors like technological superiority or timely epidemics accidentally brought from the Old World. Every time they established control over some part of America, Africa, India or the Pacific, you could bet they did with the support of indigenous who gifted them large amounts of troops, intel, supplies, guides, resources and all they needed, often obtaining massive political and socioeconomic benefits in exchange. Note that many of those examples qualify as collaborateurs solely from our modern standpoints of race and geography; before the Iberian empires unified politically their lands, few tribes had real reasons to consider themselves any closer to the tribes they were helping to conquer than to the bearded foreigners organizing the whole thing (which became even blurrier when mestizaje or mestiçagem caused racial barriers to become almost irrelevant by themselves alone).
The Conquest of Portuguese India saw the Portuguese navigators allying themselves with every Indian state willing to support or at least allow their war effort against the local Islamic powers, usually in exchange for commercial conveniences. Among those were the states of Cochin, Cannanore and the Vijayanagara Empire. Even when they conquered the remote city of Malacca, they did so with the help of local populations of Chinese, Burmese and Indians.
On the road there, while circumnavigating Africa, the Portuguese also tied commercial alliances with the great African kingdom of Kongo and the Imbangala brotherhoods, who were huge on the idea of selling a slave or two to the foreigners - which is basically how the Atlantic slave trade started, with blacks capturing, enslaving and selling other blacks. Ironically, while a prime slaveholding power, Portugal was also oddly keen in integrating black people as soldiers, mercenaries and officers in their overseas armies, like Spain would do with their remarkably numerous conquistadores negros. At the time, finding blacks owning other blacks as slaves in the Indies and Brazil was far from rare.
Hernán Cortés planned and achieved the Spanish Conquest of the Aztec Empire by allying himself with the Aztecs' many enemies and discontent vassals, some of which were so eager of being freed from having their citizens sacrificed in Tenochtitlan that even initiated themselves negotiations with Cortés before he knew what was going on. His first true allies were the Totonacs (coastal vassals to the Aztecs with a strategic position to hear news about seafaring foreigners), the Tlaxcaltecs (a confederacy of tribes geopolitically cornered by the Aztecs), the Texcocans of the chieftain Ixtlilxóchitl (an indigenous prince who had been exiled from Texcoco for resisting Aztec interventionism) and the Chinantecs (mountain tribes who also opposed the Aztecs). However, this alliance only grew with each new twist of the war, and by the end of the conflict, all the former Aztec tributaries were in the Cortesian side. The Tlaxcaltecs in particular received great rewards by the Spanish crown and became their biggest loyalists during centuries, even forming most of the crew of the expedition that conquered the Philippines.
The second regional power behind the Aztec Empire was the Purépecha Empire, yet another of its arch-enemies, but due to their geographical location and lack of ties to Cortés' allies or enemies, they played no role in the conflict until the Aztecs had fallen. Apparently, the Aztecs had send them envoys begging for an alliance against the Cortesians, but the Purépecha chieftain laughed in their faces and had them executed. Afterwards, seeing the state of things, the Purépechas picked the strongest side and joined the Spaniards without conflict, and later would lend a hand to the expedition of Francisco Vázquez de Coronado.
Francisco Pizarro performed the capture of the Inca emperor Atahualpa mostly with his own forces, but he was still advised by some chieftains from minor tribes, like the Tallans and Chiras, who saw Spain as a good chance to escape from Atahualpa's rule. To explain, Atahualpa had previously reached the Inca throne by revolting against his brother Huáscar, and after doing so, he engaged in savage punishment actions against all the tribes that had supported Huáscar (or merely who had not supported Atahualpa enough), leaving tons of resentment against his new rule. Naturally, when the news of Atahualpa's arrest ran throughout of the Inca Empire, dozens of those indigenous tribes flocked to join Pizarro, like the Cañaris, Chancas, Huancas, Huaylas and Chachapoyas, as well as some Inca aristocrats who preferred Huáscar or whoever was in charge now. They joined the Spanish Empire so happily that when a Huascarist nobleman of all people, Manco Inca, revolted against the Spaniards for mistreating him, most of the tribes still supported the Iberians and helped them drive Manco away.
Similarly, many local islanders helped the Spaniards during the Spanish Conquest of the Philippines and their subsequent battles with other local powers.
The name of Benedict Arnold is synonymous with treachery in the United States; were it not for his attempt to secretly hand over West Point to British forces, he may well have been considered a war hero for being one of the most competent generals in the Continental Army, earning distinction in the major victory of the Battle of Saratoga. Lack of appreciation was his primary motivation for defecting, though this was arguably self-inflicted: by all accounts, he was generally obnoxious and pretty hard to get along with.
Loyalists, i.e. American colonials who supported the English and opposed the Revolution were treated as this after the Americans won, many of them had their properties seized, and chased out of house and home to Canada, with their land grabbed by prominent Revolutionary aristocrats. This was especially common in the Southern theaters. Of course much of this was not in any way condoned by the leadership; George Washington, after the war, paid very public visits to several notorious Loyalists to demonstrate that they'd been working for him during the occupation. He also issued a note of protection to the family of John Honeyman, another collaborator/spy, and basically tried to dial down the partisanship.
Benjamin Franklin's own son was a loyalist. His father never forgave him, and in his final years, he publicly wrote his son a letter calling him a traitor who won't get a cent of his estate, noting fully well that were the Americans to lose, his son wouldn't lift a finger to help his father and the rest of his family and siblings, and generally insisting, in so many words, that he's dead to him.
German bourgeousie and intellectuals were at first very welcoming to the French during The Napoleonic Wars and greatly preferred them to their old monarchs (the general public was mostly indifferent). The forced conscriptions for the invasion in Russia tarnished this image somewhat, but to this day, the view on the time under Bonaparte is surprisingly positive.
The Indian wars often had this. The Pawnee aligned with the United States, but over time, people like Red Cloud and Spotted Tail also fell under United States influence.
In the context of European colonialism, the concept of "collaborator" is a very contentious phrase with a lot of anger and nationalistic emotions attached to it even decades after independence. A representative, and widely documented example, is the case of The Raj and The British Empire, and the circumstances leading to the partition and independence of India and Pakistan:
To begin with for the first hundred years of the Company Raj (1757-1857), the East India Company's army consisted largely of Sepoys, mercenaries recruited from India's warrior caste, including both Hindus and Muslims. They used this army to subjugate and take over many of the kingdoms, sultans, rajas, who opposed them, annexing their territory, and during the conquest, the Sepoys committed many war crimes (Rape, Pillage, and Burn during the Conquest of Sindh being especially noted), and also aided the Raj during their failed invasion of Afghanistan burning down Kabul, and reducing it to rubble. Then the 1857 Mutiny broke out, and the same Sepoys became the leaders of the largest colonial revolt in the 19th Century (not only in the British Raj but the world) and they courted as allies, the same princes, rajas and queens, they had fought against, which some did accept, but others refused. The Sikhs and Afghans refused to give aid, and despite their dislike for the English, they fought and aided them in suppressing the Mutiny. This is one reason why many refuse to consider 1857 the "First war of Independence" in India, since people on both sides have good cause to see themselves as resistance and their opponents as collaborator.
Many of the Mutineers also targeted and killed en masse Indian Christian converts, many of them being of lower-caste, seeing them as Sell-Out and traitors, forgetting who it was that made the Raj so strong for nearly a century, or that lower-caste Hindus might actually find something positive and worthwhile in the Christian faith (which while true was often coerced by British Missionaries, still found support by actual willing converts). And even decades after Independence, Christian minorities in India face low-level to high-level discrimination for not being truly Indian on account of their faith.
After 1857, the Raj actually invested heavily in promoting Indian education and investment and even encouraged the forming of Indian political parties, such as the Indian National Congress, and the Muslim League, so as to better build consensus and control the opposition as it were. During this time, they also more or less invented the Indian middle class, and virtually India's entire political class and intelligentsia (even Mahatma Gandhi) became Majored in Western Hypocrisy, and yet eventually they formed a prominent core of the Indian Independence movement, and on coming to power in The '40s, they opposed the "princely states" led by native rulers (with titles like nawab, nizam, sultan, raja, maharaja, etc.) who became voluntary vassals of The British Empire in exchange for official protection and cementation of their local authority, a system formed to keep them in line after 1857.
The Indian Army, aka Kipling's Finest was a highly segregated unit tasked with helping the English govern the country, and suppress local rebellions (it's often forgotten in India, that the regiment that carried out the famous Amritsar Massacre at Jallianwalla Bagh, comprised mostly Indians, albeit the officers were English). During World War II they fought against Nazi Germany and Imperial Japan. Meanwhile, the Indian National Army, formed by "Freedom Fighter" Subhas Chandra Bose fought with Imperial Japan against the same. From the perspective of Indian nationalism, at the time, and in post-independence events, Bose is a hero and the Indian National Army became the model for the post-independence military even if it was military negligible in Japan's war effort, but as George Macdonald Fraser noted, many of the Indian soldiers in the British colonial army at the time, saw them as traitors and collaborators who fought one Empire while serving another.
During World War II, the Indian National Congress refused to publicly endorse and support the British war effort, and many of them were imprisoned for their riots and protests at what they saw as British hypocrisy of opposing Nazi imperialism while being imperialistic in India. In the same time, the Muslim League, the party that founded Pakistan supported the English war effort. Many in the Congress saw the Muslim League as Sell-Out for making the rational point that as bad as the British were, the Nazis were worse. This made the Muslim League such a prominent party that elections held in 1945, made the cause for the partition and establishment of Pakistan a popular idea when before it was a fringe one. And much of this anger and grudges led to the violence of Partition.
World War II
Numerous examples of varying degrees during World War II, many of which have since become synonymous with selling out one's country to foreign invaders:
The Wang Jingwei government of 1940-1944 in Nationalist China throughout the Second Sino-Japanese War. Once, he had been the peoples' favoured candidate to take over as head of the Nationalist Party and take the Presidency. He brought a lot of his popular support with him when he joined the Japanese out of the belief that the Nationalist Party forces would soon be defeated and that his defection could make the transition easier and less bloody. The Nationalists fought on and his defection made the situation worse by its effect on morale and the negative associations with the Nationalists. He ended up presiding over an increasingly powerless and unpopular regime until his death of natural causes in 1944. Though he had good intentions for the most part, for decades all people of Chinese culture knew his name as a by-word for treachery. In recent years, this has changed with Chinese and Western historians pointing out his important contributions in the Xinhai Revolution. Nowadays, Wang is seen in Chinese culture as a naive fool rather than a treacherous snake.
While Korea didn't have a puppet leader in their own country during the 1910-1945 Japanese occupation (as well as the 1905-1910 protectorate period), with Japan opting instead to simply use an ethnically Japanese governing body who reported to the Japanese Emperor, they did have a great deal of ethnically Korean families and businesses actively collaborating with the Japanese for their own benefit, both before and during World War II. Once the occupation ended with Japan's defeat, these collaborators became shunned by Korean society, with the term "chinilpa" emerging as a pejorative for them. Descendants of chinilpa have spent a great deal of their lives trying to disassociate themselves from their family histories, and surviving chinilpa were subject to legal prosecution as a result of their actions during the occupation (the term has since evolved to become a Korean-language equivalent of "weeaboo," and is generally considered just as derogatory in this new context). A similar situation occurred in China during their own occupation by Japan, with "hanjian" emerging as the Mandarin equivalent of "chinilpa". Surprisingly, many of these collaborators actually remained in power in South Korea for years after the war, when they were propped up by the United States in order to counter those Dirty Communists in the north.
The most well-known western counterpart to the Wang Jingwei were the Vichy regime in France, who were led by genuine French fascists (and some former communists and socialists) but mostly consisted of ordinary folks. Philippe Pétain's name is used as a swear word by some French to this daynote It helps that Pétain sounds a lot like putain, which literally means "whore" and is a common obscenity in France used as an expletive like "crap" or "fuck"., and the word "Vichy" likewise represents collaboration throughout the Western world — even on this very wiki. While Pétain had genuine fascist sympathies, he was also a realist who was well-aware of how fragile his bargaining position was with the occupying Germans and how vulnerable France was and surrendered while Germany's peace terms were still relatively lenient. There is no such ambiguity for his second-in-command Pierre Laval, who quickly became a true fascist at heart, disregarding his former friends in the Socialist Party. Ironically, Pétain was previously the mentor to Charles de Gaulle, the leader of the Free French forces. Moreover, the latter commuted the former's sentence from death to life imprisonment for his World War 1 efforts while Laval was immediately sentenced to death by firing squad.
Norway's Vidkun Quisling and his party Nasjonal Samling ("National Gathering/Unification") created a collaborator government after Norway was invaded by Nazi Germany. The first Quisling government was, however, dismissed by Reichskommisar Josef Terboven, who felt it would only increase resentment against the occupation (he also thought Quisling was a feckless moron), although Quisling remained as head of the "Kommissarische Staatsräte". Quisling was again allowed to set up his "own" government in 1942, in large part because Hitler (never a great judge of character) believed in him. On that note, the local Germans in charge complied, but saw to it that the puppet government adhered to their wishes, or else (one of the ministers was allegedly offed in a discreet way when the German commando found him "bothersome"). Quisling himself became so hated that the staunchly anti-death-penalty country made a special exception just for him. His title, "Minister President" was quickly subverted in Norwegian to something like "Minister Pissatrengt", which translates roughly as "Minister Full of Piss"... His name has become a synonym for collaborationists and traitors.
Even the utterly brutal Reichskommisariat colonies on the eastern front had collaborators, many of whom came from nations like Estonia who had been recently conquered by Stalin, or from the persecuted Cossacks, and thought they were fighting for their freedom. As can be seen, in real life, this trope is much less black and white.
A number of "White Russian" (the losing side in the Russian civil war) emigres volunteered to serve the Nazis, including some notoriousCossack Atamans (warband leaders) who fancied a rematch.
A complex example are those local militias who initially support the Germans as liberators from brutal Stalinist oppression, who would arguably be Les Collaborateurs to both sides - to the Soviets for siding with the Germans, and to the Germans for their eventual betrayals after the Germans proved even worse. A good example are the Ukrainian nationalists and the Lithuanian Forest Brothers, who carried on guerilla campaigns against the Soviets, then the Nazis, then both Nazis and Soviets, and then the Soviets again. Until The '60s. Some of their members also took part in Holocaustnote Most death camps had a staff consisting of native Germans and auxillary Trawniki guards, usually recruited from Eastern Europe. Quick rule of thumb: the Germans wear grey, the Trawniki wear black., and Ukrainian nationalists committed an ethnic cleansing against the Poles.
Perhaps the most visible example of this are the non-German Waffen SS divisions, who actually comprised about 50% of total SS troops in the last years of the war, and originated from a veritable smorgasbord of countries. It is notable that French Waffen SS troops were some of the last Axis soldiers fighting in Berlin.
There were several instances of militias in former Soviet territories (Ukraine and the Baltics, for example) who rather enthusiastically began slaughtering Communists and Jews, sometimes even before they had been officially conquered by the Nazis.
Soviet General Vlasov, after being captured by Germans, performed a Face–Heel Turn and was eventually given a small army to command. He and a dozen of officers under his command were captured by the Red Army and detained at the Lubyanka KGB building and hanged in 1946.
The Netherlands had the highest rate of citizens turning in their Jewish neighbors of any of the countries conquered by the Nazis (as the story of Anne Frank can testify).
Belgium proved unfortunately fertile ground for collaboration; the Nazis exploited the country's numerous ethnic-linguistic groups (especially the French-speaking Walloons and Dutch-speaking Flemish) for their own ends. For the Walloons, the Rexist Party led by Léon Degrelle organized collaborationist militias for suppression of anti-German elements. The Flemish National Union, a pan-nationalist Dutch movement that advocated merging Flanders with the Netherlands, also sided with the Nazis. The Nazis appointed leaders of these groups to prominent political positions, where they assisted in rounding up Jews and Resistance fighters. The SS also recruited up to 40,000 men Belgians in two divisions, the Legion Wallonie and Legion Flandern, which both saw heavy action on the Eastern Front.
Goebbels predicted that American Indians wouldn't be loyal to America. This started with the assimilationist American Indian Federation and its association with the German-American Bund and Silver Shirts. That the swastika is associated with Shock and Awe in Indian cultures was another reason Goebbels thought Indians would support him. As one final push, Germany declared the Sioux to be Aryan. Ultimately, however, it was Defied by the Indians, most of whom were 100% loyal to the United States — the Sioux Nation declared war on Germany even before the US did.
On the other side of the war, we have Thailand, which sided with Imperial Japan. note (Although Thailand mainly sided with Japan as a way to exact territory and concessions in Cambodia from France, and because Phibun wanted to spare the nation the brutality of outright conquest by Japan.) Understandably, relations between Thailand and China and both Koreas are strained to this day. The same goes for Iraq.
Speaking of Iraq, a lesser known campaign in the war occurred when the pro-Allied government in Iraq was overthrown by a pro-Axis faction in a coup. The Nazis wanted a friendly Iraqi government to combine with the already pro-Axis government in Iran so that they could launch a joint attack on British India with the Japanese called "Operation Orient". Luckily, the British made short work of the rebel Iraqi forces (who were about as competent as Saddam's army in later years) and the Allied-friendly monarchy was restored, Denying Germany a pathway to Asia.
The Indian National Army was the brainchild of Bengal socialist Subhas Chandra Bose), who'd witnessed British leadership ravage Bengal with some of the worst famines in human history. After failing to secure aid from the Soviet Union (soon to be a British ally), he created his independence-minded army with help of Japan, staffed by Indian POWs taken by the Imperial Japanese Army. After the war, and Bose's death, the British government of India made a point to Un-person the campaign out of fear of further rebellions and put officers on trial for treason—the last thing India and Pakistan ever agreed upon was defending the accused.
Zigzagged in India itself. Bose and INA are considered heroes of India's fight for independence against The Empire, the British Empire. The international airport of Kolkata is named after Bose. He and fighters of INA have been honored in numerous commemorative stamps. British attempt to put on a show trial to condemn the officers of INA backfired spectacularly as it prompted mass protests throughout India that made the country ungovernable and was a key contributing factor to the precipitous collapse of the British rule in India.
In a truly bizarre example, the Nazis formed a small regiment of the SS called the Tiger Legion consisting of Indian members. Yes, folks you read that right...Asian Nazis! Hitler claimed the Indians were somehow Aryan to explain it, but still.
Why, Nazi racial theories notwithstanding, lots of Indians are Aryans. They call it Indo-Aryan peoples for a reason. And Hitler even proclaimed the Japanese "Honorary Aryans" because they were a major ally.
The Philippines had the "Makapili", who collaborated with the Japanese during the occupation of the islands. Notable collaborators included former Philippine president Emilio Aguinaldo and lawyer and judge Jose Laurel, whom the Japanese installed as president of their puppet regime for the islands. Most Makapili were wealthy landowners who feared a working class uprising, and turned to Japanese fascism due to its opposition to communism. The uprising that the landowners feared did occur during the war, in the form of Filipino guerilla resistance against Japan. Much like in the case of Korea, many Makapili were granted broad amnesty by the Americans after the war, and were put in charge of the newly independent Philippines in order to suppress the guerilla uprisings that had broken out during the Japanese occupation, as many Filipino guerillas were in fact communists.
The Ustaše or Ustasha regime in Croatia were probably the most hardline among all the Nazi collaborators. The structure of their organization closely mirrored that of the Nazi party, they sent a substantial number of troops to the Eastern Front, and were the only non-Germans to run an extermination camp. Despite initially having substantial support, their brutal campaigns of genocide against Serbs, Jews and Roma soon alienated most of the population, who ended up joining the Yugoslav partisans under Joseph Tito (if nothing less because they saw him as the lesser evil or greater good, depending on who you ask). The atrocities carried out by the Ustaše were so sadistic that the Nazis were shocked at reports from Croatia. Today, the term "ustaše" is either used as a derogatory term for Croatian ultranationalism, or as a mocking term against political opponents in Serbia. (i.e., Slobodan Milosevic was referred to as "ustaše" by his opposers towards the end of his rule.)
Zigzagged with various Southeast Asian pro-independence leaders who collaborated with the Japanese (at least initially) against their imperial overlords—Aung San and Ba Maw in Burma/Myanmar, Sukarno in Indonesia, and Subhas Chandra Bose in India. All these leaders are at least highly regarded (and in some cases deeply revered) by many in their home countries today because they are seen as La Resistance against The Empire rather than Les Collaborateurs. Of course, they are viewed highly negatively in Europe as opportunistic war criminals who received a Historical Hero Upgrade from the various patriotic movements. For instance, under Sukarno's collaboration, the Japanese killed at least 4 million Indonesians, put all Dutch and mixed Indo-Dutch residents into concentration camps for the duration of the occupation (where many were also starved and tortured), forced numerous Indonesian and Dutch women into sexual slavery, and plundered the country to an even greater degree than the previous colonial regime.
Within the system of concentration camps, a number of inmates, many of them Jews, were recruited as Kapos, whose role was to maintain order in the camps. To do so, the SS issued them batons, and were often feared as much, if not more, than the SS guards because they would rat out their fellow prisoners, or beat the other inmates senseless, if it meant that they (the Kapos) could live another day while everyone else around them was herded into a gas chamber. The Kapos were selected by the SS from all the incoming groups of "undesirables" with favoritism toward criminals who would already be familiar with the rules of intimidation and bribery used to run the camps. The purpose was to minimize the number of SS troops required to keep the camps running, and Kapos could expect relatively cushy treatment. Once the Allies liberated the camps, and realized what their purpose was, the Kapos often met the same fate as their SS-Totenkopfverbände overseers.
Death camps also had collaborators in the form of Sonderkommandos, workers isolated to handle the monumental and gruesome job of corpse disposal. While Sonderkommandos earned slightly better living conditions, their first-hand knowledge of the camps' ultimate purpose also marked them for death. At long-running camps like Auschwitz, the SS went through as many as 14 "generations" of Sonderkommandos.
The ghetto police were Jewish inmates in the Nazi ghettoes who agreed to work with the Nazis and avoid deportation. They assisted in the rounding up and deportation of Jews to the concentration camps and were organized by the Judenrat, a council of Jewish elders who presided over each ghetto and oversaw the deportations. Of course, when the ghettoes were liquidated most members of both groups were themselves deported to the camps.
On a related note, Group 13, the so-called "Jewish Gestapo", was a collaborationist network based in Warsaw. It operated as a secondary police force within the ghetto and had informers placed inside Jewish underground groups, although in practice it was mostly used for smuggling and extortion. After the group was dissolved and most of them were exterminated, the survivors set up the Żagiew, a similar group that infiltrated and exposed Jewish resistance movements and lured Jews into traps where they would be robbed and killed.
In addition, there were Jews such as Ans van Dijk and Stella Goldschlag who were uncovered by the Nazis and helped them to capture other Jews in return for protection from the Holocaust.
Even Britain was not immune to this trope. The British Free Corps was a paramilitary group that fought alongside the Wehrmacht and was composed mainly of British and Canadian prisoners of war who had been convinced to defect to Nazi Germany in return for release. Since the UK did not surrender and most of their soldiers retreated at Dunkirk in 1940, there were not enough prisoners of war for the Germans to recruit from, and even fewer who were willing to defect. It never reached the size of an actual corps, with a maximum strength of 27, i.e. a small platoon.
French couturier Coco Chanel was (willingly) part of a German operation to try and open secret negotiations with Churchill and attempt to get the British to sign a separate peace agreement. She also used the occupation to her advantage while trying to get full control of Parfums Chanel (which makes Chanel No.5 perfume), using the Nazi seizure of Jewish property and businesses, since the owners were Jewish. Turns out the owners (the Wertheimers) had seen the Nazi policies coming, and had turned over control to a Christian businessman, who handed it back after the war, before fleeing to New York. Part of why the Wertheimers didn't make this more public during their post-war legal struggles was that, while telling everyone that she was involved with the Nazis would help them win the case, it would also make it a bit hard to sell anything with her name on it..
The biggest controversy in the life of Tintin creator Hergé was the question of whether he could be considered a collaborator or not. During the war, he continued to work for the Nazi-controlled Le Soir, even as it printed anti-Semitic and anti-Allied propaganda (in which he was not involved). After Belgium's liberation, he was denounced as a collaborator by Belgian Resistance groups. A judicial inquiry into his case urged leniency, considering the prosecution of "the Tintin man" to be a step too far, but did note that Tintin's fame attracted readers to Le Soir. Post-war, he was approached by a former member of the Royalist Resistance (the conservative resistance group) who arranged for Hergé's record to be checked before he could be given a certificate to work again. Again, their verdict was that he was "a blunderer, not a traitor" and he was cleared of any collaboration. But needless to say, the spectre of Nazi collaboration hung over him for the rest of his life.
Other modern examples
In Iraq, rebelling factions often execute Iraqis working with the US-backed government, accusing them of collaboration.
The Taliban have executed their own people on accusations of spying, including a a seven-year old boy and a 70-year old woman.
From time to time residents of Gaza and West Bank (whose over one-fifth of the working population is employed in Israel) get executed by local militants under accusation of collaborating with Israel. Evidence is rarely offered, let alone a trial.
In Vietnam, the Republic of Vietnam (better known as South Vietnam), which existed during The Vietnam War and ceased to exist in 1975, is viewed as this.
Due to his role in creating the union of Ireland and Great Britain, and his violent suppression of the Irish Rebellion of 1798, Lord Castlereagh was often seen as this by his fellow Irishmen. His best friend, The Duke of Wellington, was also Irish and gained a similar reputation, though he is today remembered for other reasons, while Castlereagh is mostly just thought of as having betrayed his countrymen by defecting to the English.
It appears Vladimir Putin intended to place his Ukrainian friend Victor Medvedchuk at the head of Ukraine had Kyiv fallen. This didn't happen due to the failure of the Kyiv offensive.
A number of Russian-appointed local administrators of the occupied/annexed zones have been targeted (usually via bombs in cars) by Ukrainian loyalists/resistants. Some got killed.
The fast advance of the Russian troops in Southern Ukraine in the early months of the invasion has been partly helped by local collaborators as well.
