Milestones quotes an interesting passage from Inventing Japan. Compare post-war Japan to present-day Iraq:
Tokyo endured [the] winter [of 1945-1946] on the workings of an illegal economy. The black market encompassed thousands of sellers and millions of buyers dealing in every commodity of daily life. It was also a vast jungle of lawlessness that began with thefts and led to gang killings, turf wars, and casual murders, becoming at last a criminal demimonde of immense proportions. It embraced all classes and kinds of people. When the war ended, sake, bread, clothing, shoes, sugar and blankets had disappeared from military depots all over the country, pilfered wholesale by officers and enlisted men alike. Small thefts were the routine of daily existence. A bicycle snatched at Ueno’s railway station turned up repainted and for sale two hours later at the station in Shimbashi. Koreans and Chinese, forced-labor immigrants during the war, prospered with goods smuggled from Hong Kong and Taiwan, and by the Occupation’s ruling, they could not be arrested by Japanese police.
It was the beginning for many mobster organizations, some of whose descendants still operate today. In Tokyo there were eight major syndicates, each with its own piece of turf around the major train stations…They fought amongst themselves and against other gangs, the Japanese mobs battling constantly for territory against the Koreans and Chinese. Guns were plentiful, another result of looted army depots. Unable or unwilling to intervene, police let gangs have at one another, and the shootouts continued for several years into the Occupation. One day in April 1948, two gangs — one Japanese, one Korean — fought it out with pistols in the Hamamatsu district. The next day, about one hundred Japanese returned to the attack on the Koreans’ black market there and killed or wounded more than 15 men.