1. Cosa Nostra - Italy
Cosa Nostra is a long-standing criminal gang in the Sicily region of Italy, home to Italian-origin gangs that have made waves across the United States and Europe. Cosa Nostra was established by an alliance of noble families, wealthy and powerful in Sicily at the beginning of the 19th century. During World War II, when Mussolini's fascism ruled Italy, even the fascist government had to partly fear Cosa Nostra. Based on its influence, Cosa Nostra helped the US military land in the ports safely and secretly, while also liaising with other revolutionary forces and allies throughout Italy. It can be said that Cosa Nostra owes much to the US government, as through that secret protection operation, Cosa Nostra received a lot of money to rebuild its power in Italy, and also had the opportunity to expand its influence to the newly emerging imperial country.
The operating principle of Cosa Nostra is an alliance of powerful mafia families, each family occupying a territory, controlling different areas, and the head of the alliance: Capo di Tutti Capi (The Boss of all Bosses) will act as an intermediary to reconcile all conflicts. The symbol of Cosa Nostra is the octopus, with the idea of spreading its tentacles everywhere in the world. Even when the head is cut off, the tentacles still function.
One of the most famous leaders of Cosa Nostra is Lucky Luciano - the one who protected US soldiers during World War II. In 1946, when the war ended, Luciano developed a global heroin trafficking network, with supply sources from the 'drug paradise' the 'Golden Triangle' to everywhere in the world. The most famous Cosa Nostra families: Magaddino, Vizzini, Corleone, Falcone, Piccolo.
Ten Commandments of Cosa Nostra:
- No one is allowed to introduce themselves directly to another member of ours. There must be a third person acting as an intermediary.
- Never peep at the wives of your friends.
- Never allow yourself to be seen with the police.
- Do not go to bars or nightclubs.
- Always be ready for Cosa Nostra, it is an obligation. Even if your wife is about to give birth.
- Must always respect appointments.
- Must respect the wives.
- When asked about any information, you must tell the truth.
- Do not embezzle the money of others or other families.
- People who are not allowed to become members of Cosa Nostra: If they have close relatives in the police force, if there are people who lie in the family, behave badly, and have no morals.

2. Cartel - South America
Cartel is not actually a gang, but rather a coalition of drug trafficking gangs in the South America region. Cartel primarily operates in South America, specifically in countries like Brazil, Honduras, Argentina, Colombia... and has expanded its tentacles to the United States and some North European countries. However, the mastermind behind Cartel is Mexico - a paradise for criminals.
Cartel in Mexico seems to only use jungle law on the streets in a savage and openly brutal manner such as hanging, beheading, amputation, without fearing the police and the law. They are equipped with all kinds of hot weapons and ready to resist, as well as to retaliate savagely.
Mexican police forces often have to wear masks to avoid retaliation when hunting down Cartel. The danger and cruelty of Cartel have been depicted in many Hollywood movies, notably Sicario, End of Watch, The Infiltrator, Breaking Bad.

3. Mafia - United States
Mafia is the name of the Cosa Nostra branch in the United States, which has grown larger and more notorious than its counterpart in Italy. Mafia is so famous that people use this term to refer to the entire underworld. Mafia began its influence in the U.S. during the wave of Italian immigrants. At this time, Mafia was still weak and had to use the policy of 'black hand,' terrorism, and extortion from its own compatriots in the United States. In the immigrant neighborhoods of New York, Mafia had to compete for territory with gangs of Irish immigrants.
Mafia officially flourished thanks to the Prohibition in the United States. With its smuggling capabilities, along with the supply of alcohol from its homeland Italy, Mafia quickly grew powerful, becoming wealthy and influential in the underworld in the U.S. During its golden age, Mafia amassed 26 major families controlling all corners of the United States, with the five most powerful families leading in New York, namely Bonnano, Colombo, Gambino, Genovese, and Lucchese. At this stage, Mafia not only controlled the underworld with all drug trafficking, arms trading, smuggling, nightclub ownership, protection rackets, but also infiltrated labor unions, business enterprises, hijacked financial sectors such as banking, embedded people in police departments, and even infiltrated political parties.
One of the most famous works about Mafia is The Godfather by Italian-American author Mario Puzo, adapted into the famous trilogy of the same name. The character of the godfather Don Vito Corleone was creatively based on the real-life figure Frank Costello - who was once considered on par with Lucky Luciano; meanwhile, the character of Don Michael Corleone - the successor godfather, was built based on Salvatore Bonanno - the godfather of godfathers of Mafia in New York.
For these reasons, Mafia is one of the Top 10 most dangerous criminal gangs in the world.

4. Yakuza - Japan
Yakuza is a nationalist-oriented criminal gang with significant influence in Japan. Members of Yakuza span all social classes, from daring gamblers to executives of major corporations in Japan.
Yakuza originated in the Edo period, initially as small criminal groups. During the Tokugawa shogunate, tens of thousands of unemployed samurai, lacking a livelihood, were forced to join Yakuza. In 1881, Yakuza formed the 'Black Ocean Trading Company,' specializing in piracy and murder at sea. In the 19th and 20th centuries, Yakuza became a paramilitary force for political factions, making Yakuza bosses powerful, including the influential boss Inagawa.
Yakuza has strict codes, notably the rule that all members must obey superiors and the rule that the gang will protect its members if anything happens outside society. Unlike Mafia gangs or secret societies like the Triads, Yakuza operates openly, sometimes pursued by the police, but usually only typical criminals are targeted, as the government generally does not oppose Yakuza. Many influential figures in business, academia, and politics secretly join Yakuza. At times, the Japanese government has relied on Yakuza for assistance, such as in the earthquakes in Kobe 1995 and Tohoku 2011, where Yakuza donated millions of Yen in non-repayable aid to victims in Japan.

5. Triad Society - Hong Kong
Triad Society (English name: Triad), also known as the Hong Kong Triad or the Triple Union , is a notorious criminal gang in Hong Kong, China, which has expanded to many other countries in both the East and the West.
The Triad Society originated from Shaolin monks favored by the royal court, with the intention of 'overthrowing the Qing and restoring the Ming,' similar to the Heaven and Earth Society. The Triad Society gradually lost control and fell into the hands of various political factions, eventually drifting to Hong Kong. Here, the Triad Society became the most infamous criminal gang. The Triad Society gathers many small gangs, engaging in all illegal activities: drug trafficking, prostitution, gambling, protection racketeering, usurious lending, contract killing, and more.
Among the small gangs belonging to the Triad Society, the strongest in Hong Kong, Taiwan, and Macao are 14K, Sun Yee On, Wo Shing Wo, and Wo Hop To. The Triad Society also extends to countries with large Chinese populations, but its strongest presence is still in the United States, the United Kingdom, the Netherlands, and Australia. Here, the Triad Society has become a powerful criminal force competing with indigenous criminal forces.

6. MS13 - United States
MS13 is short for Mara Salvatrucha gang, originating from the United States and has spread to many other countries in Europe. The number of MS13 members in the United States alone is estimated to be at least 70,000, primarily engaged in drug trafficking, arms trafficking, human trafficking, and contract killing.
The gang was founded in areas bordering Mexico by Salvadoran immigrants to the United States, who were then pressured by Mexican Cartels and American criminal gangs. Initially formed for self-defense, the gang gradually expanded, competing with Cartel forces on US soil. In 2006, an MS13 leader named Ernesto Miranda was assassinated by the Cartel at his home shortly after completing his prison sentence.

7. Bratva - Russia
Bratva is a notorious criminal organization in Russia, often known by the English name 'Brotherhood.' The precursor of Bratva appeared during the reign of the Russian tsars. During World War II, Bratva had the opportunity to consolidate various disparate gangs into a powerful organization, contributing to the camouflage and support of the Soviet Red Army.
During the Cold War era, Bratva was considered the 'iron hand' of the government to control civil society. However, with the collapse of the Soviet Union, Bratva officially lost control and entered the path of organized crime. It is estimated that Bratva brings together over 6,000 small groups operating throughout the territory of Russia and Eastern Europe; some tentacles have spread to Western Europe, the United States, and China. Bratva has received more than 200 global arrest warrants, becoming one of the Top 10 most dangerous criminal organizations in the world.

8. Bloods - United States
Also a gang of African Americans in Los Angeles, Bloods are the arch-rivals of the Crips. The attire of Bloods is red, contrasting with the color blue.
Bloods and Crips frequently engage in hot gun battles on the streets, mainly due to territorial disputes, business conflicts, drug trafficking, and street clashes. However, as both gangs have become prevalent, just seeing each other results in a 99% chance of conflict. It is estimated that these two gangs have over 200 clashes each year, with casualties reaching nearly 1000.

9. Crips Gang - United States
Crips is an African American street gang founded in 1969 in Los Angeles, California. While the mafia is a high-level criminal gang federation, infiltrating into the financial world and banks, Crips is a street-level gang originating from the ghettos of African Americans.
Crips has about 30,000 to 35,000 members, primarily involved in drug trafficking, arms dealing, nightclub protection, prostitution, and more. The distinguishing feature of Crips gang is their Hip Hop attire in blue. Many famous rappers of the time were also members of Crips, notably Snoop Dogg and Tupac.

10. Aryan Brotherhood (AB) - United States
And the final name in the Top 10 Most Dangerous Gangs in the World is AB (Aryan Brotherhood). This gang was founded by the most dangerous underworld figures, imprisoned for life sentences or death penalties. AB has become a terror in every prison in the United States, comprising 20,000 members both inside and outside prison walls.
AB establishes networks for contract killings, protection, and supplies everything that inmates demand, as long as they pay in full. The condition to join AB is to commit a murder inside prison as they require.
