Radical Islam is waging war against the West. Whether sent from the middle east, trained domestically, or self-radicalized, this is the true face of the war on terror, and the war OF terror.
We cannot win this war with weapons. No force of tanks or aircraft carriers is going to stop these events; indeed, each jihadist killed is a martyr to their cause.
We need to fight ideology with ideology of our own. Challenge their ideas with our own, respond to their words with our own. If western civilization is worth defending, then it needs to stand on its merits and show its strengths. Silencing opposition is avoiding the confrontation.
If people want to blow themselves up, threatening them with death will do nothing to dissuade them. What we need to do is to convince them not to; not to address the violence, but to address the motivation to cause violence. Anything else feeds into their narrative, diminishes our own ideology, and spurs the cycle.