SUMMARY by public safety for the duration of detention, but also for the long-term aims of rehabilitation, treatment and other individual interests. This also enforces an adequate offer of care, which suits the risk for recidivism and which is equivalent to the care outside detention. With the ISD it is necessary that authorities concerned will hold the view that the two-years detention is primarily aimed at contributing to solving the individual offender problems. By that, not only an individual interest is served, but also the currently prioritized collective interests of public safety and prevention of recidivism. Moreover, this chapter discusses the research question and provides answers. First, the positioning of the ISD in the historical development of the Dutch penal sanction system with regard to combating recidivism and criminal nuisance is discussed. Based on the foundation, the legitimacy of the statutory regulation, the objective, the offender target group and the execution of this particular sanctioning, it is concluded that the ISD fits within a broader, long-term and lasting development. In many ways, the ISD builds on aspects of the labour colony penalty, the statutory regulation for recidivism, the criminal custody measure and, especially, the SOV. This development appears to be continuing, considering the bill introducing minimum penalties for recidivism of severe crimes, as well as the bill introducing a restraining criminal measure to impose, for example, area injunctions on offenders. Because this past and future development together concern the criminal theoretical dual system of a penalty and a criminal measure, the minima and maxima of the applied sanctions, the conditional or unconditional detention and finally, the restraint, it is concluded that for the last 125 years the legislator has wanted to make full use of the penal sanction system to combat recidivism and criminal nuisance. When social problems are indeed so severe that a certain use is necessary, this broad sanctioning can in principle be legitimate. However, a less simplistic and functional legitimation is needed. Furthermore, there is a need for an integrated, systematic revision of the penal sanction system. The conclusion that the ISD fits within a broader, long-term and lasting development leaves unimpeded that there appears to be no lucid, constant, balanced development. ... etc.