The Japanese police intelligence was politicized at some point. The authoritarian oppression has been problematic enough, but it is not political, philosophically. The actual Japanese intelligence has had their political direction, which has been more than just being authoritative.
The Japanese politics had had a stable system until the early 1990s for almost forty years, the ruling liberal democratic party against the minor socialist. However, the LDP was divided around that time due to several corruption cases.
Looking at the detail of those events, there was no sign of the police intelligence, surprisingly, which meant they were not politicized yet. Other police divisions were involved in this investigation and there was no room for the intelligence.
In the late 1990s, the internal system called as “IS” was established in the police department. It is a process to gather all the information related to security, politics and even ordinary criminal tips sending up to a director of the police intelligence, eventually to the director general.
As a result, the police intelligence could handle more political information to manipulate the politics and politicians. There is another crucial technology which is an electromagnetic wave. This technology was hidden even to the other police divisions, which was how the intelligence had ruled this power.
Although, these capabilities did not make them politicized, which meant the politicization should have been a result of the external reason, not from the internal structure.
The most probable answer is an extension of their student movement, tilted toward the left extremist in Japan. The vast majority of the ranking officers had graduated from the university of Tokyo, the top school in Japan. They passed a senior exam for the director candidate when they were students and hired at the police department. I assumed they hired around thirty graduates every year, even at the time of rising student movement.
It basically meant that the police should have hired some of the left extremists leaned graduates as a director candidate. It was a story of 1960s and 1970s, but they were actually able to rule a critical intelligence position in 1990s and 2000s.
Researching a background of the senior intelligence officers, some of them have actually affected by the communism and socialism in those days. They have been believed not being radicalized to the left for decades, but they got the power in the end to utilize it to their ideology.
That was why the police intelligence was politicized especially toward the left extremist and I had much evidence for that direction.