you can't compare the American Mafia with other OC groups; Crips and Bloods are numerous but for the most part consist of bands isolated not connected to each other, the Mexican drug cartels with the exception of the leaders are composed of members recruited to kill as much people as possible and then post the videos on the web, an example is the Mexican drug war, which broke out between the cartels and the Mexican state that has done 60,000 victims and in a few years with the Mexican state that is losing.

same thing for the other drug cartels in South America.

is impossible to compare the Triads or the Yakuza

In fact, in China in members of the triads are very numerous because being a corrupt country fails to curb the problem, is distinguished by the triad tong which is a more violent version being composed by the worst of the worst from people that is not accepted by the triads.

The Yakuza is a special case, in Japan there is a law such as RICO or italian 416 bis punishing participation in criminal enterprises, for which the various families of the yakuza have a total of 103,000 members.
This means that you can be part of the yakuza (to let you know is if the 5 families of NY businesses were legal, they had their own home and the wiseguy could infiltrate any society all in the light of the sun) and will be eventually punished only when you do something that comes from being part of the yakuza (murder, drug trafficking, etc.)


The Russian mafia is rightly considered as the most vicious and ruthless, having made in just 22 years since 1992 what the American and Sicilian mafia have done in a hundred years it comes out of the 300,000 members russia and ten times as much in russia.
with the fall of the USSR have filled the world with weapons they had stolen in the Ukraine, from army depots (as seen in lord of war) is also said to be the only mafia have nuclear warheads that would steal from the countries former USSR, it is actually more likely to sell plutonium.

I know this if I will remember something else I'll write it.