We all send our sympathies to the people of Paris who faced a series of barbarous attacks last night. Our thoughts are with the families who have lost loved ones.
The western intelligence agencies do often intercept and prevent such atrocities. When an attack gets through it provides additional incentive to improve and augment the Intelligence effort. Such events lead governments to take action after the event which may be counter productive. Disrupting the lives of many and changing the normal pattern after all the attackers are dead or arrested gives the terrorists an extra win.
Free and open societies are vulnerable to such madness and badness. Each of the gunmen was someone’s son, or brother or other friend or relative. The authorities need the vigilance and support of all of us, as they are only as good as the evidence and information they receive or collect. None of us want to live in a society of spies and informers, but we do need to think our neighbours and fellow citizens would report conduct that could be the prelude to mass murder.
The other thing we need from the authorities is a rapid and decisive response as soon as any armed incident is reported. Potential assassins need to know they are likely to be killed before they can kill many.