Background Information
The game more or less takes place after the 2nd Season of the TV show, or SAC 2nd GIG, directly after the attempted genocide of the immigrant population within their borders. Although the widespread destruction of the immigrants was averted, the tensions between the Japanese people and the Asian immigrants were not, and were reignited soon after as conventional conflicts waged on with the Japanese police and military. Although after a while With Humanitarian rights issues being claimed on both sides (and to some extent true on both sides), both international and local forces have been called in to help manage the emerging crisis. Further complicating the issue has been the influx of approximately 4.5 million more immigrants, raising the number to some 8 million in the current state. Many of them have been relocated to the Kantō region, an area destroyed in WWIII by nuclear bombs, that although scrubbed with micro-radiation cleaners after the fact, has still remained contaminated for decades. While a generally unsafe place to live, the time and the microtechnology has dampened the radiation substantially, but it is still generally considered unlivable. As a result, the refugees that reside there either suffer from health problems or are forced to wear gas masks and NBC suits at all times.
The rampant crimes and frequent riots in the immigrant community, as well as the violence and clashing of paramilitary forces previously lead by Kuze (now deceased) has lead to friction with the general populace and the immigrants in general, by bigotry and violence on both sides. To Help put an end to the issue, Joint Task Force 252, which includes Section 9, have been tasked on shutting down the violence and working towards peaceful resolution to the conflict. Section 9 is considered ideally suited for the environment for three key factors, the initial one being their military experience and skill in combat, their second being a crime detective organization and an emphasis on tracking down individuals responsible for crimes, and their psychological insight to the immigrants and the criminals they track (as well as their theories on philosophy and human psychology) allowing to more easily understand and make peace with the opposing forces. Furthermore, as a result of Aramaki's close concert with the then sitting Prime Minister of Japan and their saving of the immigrants and prevention of international war, Section 9's role and budget has been expanded substantially. Their successes in the operations as well as their direct role in saving the lives of millions of people has elevated their status both in politics and the public eye, and allowed them to grow exponentially. Section 9 now possesses over 100 operatives, and is seeking to recruit nearly 300, with the original team at it's core and serving as leaders. Built like a military special forces teams, they are incredibly unorthodox in their operations and rely heavily on the close cooperation of the member teams. Their experience in guerrilla warfare makes them ideally suited for an enemy embedded within the civilian population, I.E. criminals hiding among civilians. With the ramping escalation in violence, terrorist attacks, bombings and hostage situations, the need for a force that can act both as domestic police and as a military has never been as poinent as this.
Section 9's expanded role and size has lead to an increase in power, and a need for recruitment. Thousands of volunteers apply annually to the organization, but only a few handfuls make it successfully each year. Recruitment comes from the military, police and even civilian populations, with the demand not only focusing on experience and skill, but a versatility in abilities and ways of thinking. The most important ability required is to be able to think outside the box and like the enemy, which requires members from all walks of life in the organization, just like the original section 9 team. The diverse array in skills, as well as the level of ability required, makes members suited for the organization particularly rare, especially considering the additional need to work well in a team and think critically on trends in human nature. With both the laughing man and immigration case solved by observing the nature of human actions, a priority is present on human thought among all other factors. Their increase in size has also been helped by poaching from other now defunct organizations, such as those ran previously by Kazundo Gōda.
Section 9's expanding size and role
"Think about it; Section 9's greatness weakness is numbers."- Major Kusanagi Motoko
After undergoing it's destruction and rebuilding phase and being threatened with annihilation, twice, Section 9 has developed considerable influence not only in politics in general, but with the Prime minister herself. These connections have allowed for Section 9 to flourish, but to avoid problems they experienced in the past, will need to build in to a full size police unit, with a public wing, so they can't be targeted with. Section 9 has already built a reputation for uncovering corruption in the government, but is now focusing on regular street crime as well, to expand it's involvement in the community and prevent the organization from being targeted by other police networks. After being targeted by both Kazundo Gōda and members of the Narcotics Suppression squad, to avoid internal conflict within he organization they've decided to expand, becoming an official organization working for the police. The larger size not only justifies the extensive spending, but provides a buffer between them and the rest of the police. It also expands their role away from corruption-only scandals, which tend to create friction with other departments, with IA or internal affairs often viewed suspiciously due to their role in prosecuting other cops. This ability to operate publicly creates greater room to operate legally, but still keeps them anonymous enough to continue their covert activities.