The West's ultimate problem is that its leaders are trying to oppose a coherent, internally-consistent (whilst also evil and wrong) philosophy with mere will-power. In the long term, to "immunise" people against those strains of Islam, you need a replacement which is also coherent. Merely decreeing that (paraphrasing) 'we will stand united', 'we must not give up our resolve', etc., is not a potent long-term strategy. You need a foundation to erect a building that has hopes of lasting.
As a historical fact, the origins of Islam do not support the idea that Islam was intended by its founder to be a peaceful philosophy. There is a real historical difference between a Jesus who died on the cross for the sins of his enemies, and a Muhammad who raised an army to slay them. The idea that these two historical foundations can ultimately and consistently lead to the same outcome - followers who reject the idea of slaying their enemies - is wishful thinking. We wish it wasn't so, but wishing won't prevent real-world beheadings in future any more than it has in the past.
This is an unsolvable problem for secularists like the author of the above article. It's an unsolvable problem for the British nation as a whole. Without a change of heart and a work of the Holy Spirit, all such problems are unsolvable. Sin makes a huge, tangled mess. The ultimate untangling can only be through a work of God's grace in Jesus Christ. Unless God gracious restrains it, there is much more to come of not only these intellectual dead-ends, but of the horrible events seen in the streets of Woolwich when their inner contradictions work out in practice. Let us who know the true God pray that he will have mercy on us, because he is full of mercy.