Since the 1970s, the Dutch anti-radicalization strategy has been characterized by a close collaboration between police, welfare providers, community groups, and national and local governments. This comprehensive approach aims to identify individuals at risk of radicalization at an early stage, offering them alternative life paths and robustly responding to imminent threats. The comprehensive approach generally enjoys considerable support among professionals, politicians, and the populace at large. However, a swelling tide is asking for more evidence that this combination of “soft” and “hard” interventions is working. Parliament is asking the government to take more measures against emerging extremist threats, but also demands more proof that these measures are effective. Liberal parties in parliament are critical of the financial and societal costs of counter-terrorism and anti-radicalization measures, while right-wing parties worry the government is not tough enough. Over the past five years, the Dutch government has commissioned multiple evaluations. Specific incidents, such as the shooting in Utrecht on 18 March 2019, have been extensively evaluated. A more general review in 2015 examined the counter-terrorism policy as a whole, finding that the ideas for the comprehensive approach were sound; yet, that the investment of ministries in this approach fell apart in the perceived low-threat period, making the intended “comprehensive” strategy become a pick-and-choice approach. Currently, the national and local governments involved in anti-radicalization efforts keep asking for more evaluations. The Ministry of Social Affairs created an evaluation toolkit, which local governments can use to evaluate interventions. The City of Arnhem commissioned a review of its anti-radicalization efforts, which is mainly able to assess the plans and processes, but not yet the outputs of the interventions. Moving forward, more collaboration may be needed within or even between European countries to amass sufficient data to enable full effect evaluations.