This is not just theory. Doing away with fundamental rights in the name of security is dangerous. In the 1970s, the UK interned hundreds of suspected IRA supporters in an effort to quell the civil war in Northern Ireland. However, in the following months, conflict increased dramatically.
Ultimately, it was admitted that this preventative detention generated greater support for the IRA. Rather than keeping the population safe from violence as promised, the policy stoked community divisions. In that case, when it came to terrorists, doing away with civil liberties caused greater bloodshed. We ignore that lesson at our peril.