A detective who specialized in organized crime once told me a dark joke: What type of crime occurs when a member of the yakuza kills another gangster? Answer: destruction of property.

The joke perhaps reflects an unwritten premise of law enforcement in Japan: as long as gangs confine their conflict to other gangs, it’s no big deal.

However, when the Yamaguchi-gumi — the country’s largest organized crime syndicate, with about 23,400 known members at the end of 2014 if quasi-members are included — split into two factions on Aug. 27, the police were understandably concerned.

Would a bloody gang war break out?

According to a report by the National Police Agency, when the Yamaguchi-gumi last broke up in 1984, a violent battle erupted that claimed the lives of at least 25 people and resulted in more than 70 injuries. The warfare took place on an epic scale: gun battles erupted on the street, assassinations were carried out and trucks were driven into the houses of rival members. In 1985, Yamaguchi-gumi members were arrested in Hawaii on suspicion of attempting to purchase 100 handguns, five machine-guns and at least one rocket launcher — ostensibly to knock off their rivals.

Seventy-three-year-old Yamaguchi-gumi leader Kenichi Shinoda, who is also known as Shinobu Tsukasa, began his criminal career in the Kodo-kai group, which is based in Nagoya.

According to the Asahi Shimbun, Shinoda had indicated he wanted to move Yamaguchi-gumi headquarters from Kobe to Nagoya.

The Yamaken-gumi, which is based in Kobe, opposed Shinoda’s plan, and 13 affiliate gang leaders in Kansai failed to attend a meeting on Aug. 27, the Asahi Shimbun said. As a result, the affiliated gang leaders who skipped the meeting were expelled Tuesday.

The rift appears to be partly historical.

In July 1989, Yoshinori Watanabe, who was head of the Yamaken-gumi syndicate, became the supreme leader of the Yamaguchi-gumi group at a ceremony in Kobe. Shinoda inherited the position in 2005 and is believed to have promoted members of his Kodo-kai syndicate to top positions in the Yamaguchi-gumi.

The Yamaken-gumi syndicate watched its power dwindle with discontent, and the Kodo-kai syndicate’s loyal treatment of kowtowing factions is believed to be another reason for the split, according to NHK.

A mid-level Yamaguchi-gumi member, who refused to be named, told this reporter that the Kodo-kai syndicate had also been singled out because of its belligerence to the police, which had led to tightening laws that restricted the group’s activities.

Indeed, the National Police Agency cracked down on the Kodo-kai syndicate in September 2009. The United States, which had sanctioned the Yamaguchi-gumi and its executives in 2012 and 2013, blacklisted the Kodo-kai and its current leader in April this year. Law enforcement agencies in Japan and the U.S. are unlikely to be too unhappy at news of the split.

While the National Police Agency warned the break-up could erupt in a bloody war, some are expecting the split may end not with a bang but with a whimper .

Atsushi Mizoguchi, Japan’s leading expert on the Yamaguchi-gumi group, told NHK he expected the odd skirmish between syndicates but ruled out a massive war.

Gang wars aren’t what they used to be, Mizoguchi says. For one thing, they’re expensive and a syndicate’s usual activities — extortion, blackmail, bid-rigging, etc. — is quickly disrupted.

These days, leaders of organized crime syndicates fear of being held accountable for their employees’ activities.

In November 2004, the Supreme Court ruled that organized crime syndicates were essentially corporations and, as such, their leaders were liable for any damages that occur as a result of one of their member’s actions. A Yamaguchi-gumi leader was ordered to pay ¥80 million to the family of a police officer who was killed in a gang war.

Tadamasa Goto, who led the last unsuccessful rebellion in the Yamaguchi-gumi in 2008 after he was expelled from the group, is perhaps a classic example of why gang leaders prefer not to engage in violent conflict.

According to the Asahi Shimbun, several of Goto’s men were convicted for the murder of a real-estate agent. The real-estate agent was killed in 2006 for blocking the sale of a building worth $20 million that Goto’s gang wanted to control and sell at a steep profit. Goto himself was never criminally prosecuted. The family of the deceased, seeking justice in civil court, sued Goto and Shinoda for damages in 2012.

Shinoda, who was locked up in solitary confinement in 2006, certainly couldn’t have ordered or condoned the hit.

Reaching an out-of-court settlement, Goto apologized to the family of the victim, paid them $1.2 million and then fled to Cambodia.

Crime, as the old adage goes, always pays, but sometimes it seems gangsters have to pay a little back for their crimes. At the time, however, it was a valuable lesson: Killing people can cost a lot of money.

Organized crime syndicates in modern times are less concerned with honor or loyalty. For them, it all boils down to the bottom-line: money. Warfare brings down heat. If a civilian is killed, the police enact new laws and business dries up.

For organized crime syndicates, the worst-case scenario in the wake of the split is that the Diet finally passes a criminal conspiracy law that would allow police officers to make arrests all the way up the food chain, close down gang headquarters and arrest syndicate leaders for all crimes committed by their subordinates, including murder.

Nobody wants that, right?

There will be no winner in such a war — except, perhaps, the police. The National Police Agency can claim success in reducing the power of the Yamaguchi-gumi group and weakening the Kodo-kai syndicate.

If the war isn’t particularly bloody and the involved parties only kill each other, then business will continue as usual.

Everyone in the underworld understands that one thing holds true in modern times: Crime does pay, gang wars almost certainly do not.

Dark Side of the Rising Sun is a monthly column that takes a behind-the-scenes look at news in Japan.