I'm getting mighty tired of the "don't change your behaviour - that's what the terrorists want" line.

I'm extremely impressed by the way left-wing compassion-mongers always know exactly what Islamic terrorists want. Apparently, "they" want us to secure our borders, instigate rigorous checks on Muslims trying to enter European countries, hunt down would-be or actual jihadists, force Muslims to accept and live by Western values (i.e. tolerance, democracy, and not killing everyone who doesn't agree with you), ban the burqa, cut off the cash supply provided by welfare payments, stop islamist indoctrination in our schools, stop child marriages, punish the systematic sexual abuse of European boys and girls by gangs of rapefugees, and imprison those who condone and carry out female genital mutilation on pre-pubescent girls. Because, you see, if we did all that stuff, it would prove that we're horrible racists, and that would incite the hordes of unemployable, sexually frustrated young Muslim men who hate the West - and whom our governments have invited into our midst - to rise up and destroy the infidel...

...Naturally the fury of the Left has been turned on those disgusting far-right bigot who fomented racial hatred and incited anti-Muslim violence by continually pointing out that allowing hordes of unemployable, sexually frustrated young Muslim men who hate the West into our midst (in the name of "compassion" or falling birth-rates or diversity or whatever) would exponentially increase the number of Europeans killed or maimed in terrorist attacks - and that doing sod-all about it was a deranged strategy.  I mean, some Muslims are absolutely adorable, so any suggestion that there's any incompatibility between our values and those of Islam is a hurtful insult to cuddly Muslims like Mo Farah and Nadiya Hussain (and, of course, to the memory of Jo Cox)! Oh, look over there - Israeli settlers. MORAL OUTRAGE!

Yeah, well, I'm not buying it. Fanatical Islamic death cult followers don't actually want anything specific from us. The cultists' "aims" are unachievable - but that's all right, because they're not meant to be achieved. In fact, their very unachievability is what makes them so attractive to inadequate, fearful, sexually frustrated young men from relatively primitive fascist societies, who feel overwhelmed by the demands and endless choices offered by modern liberal democracies. To achieve the stated aims of jihadists (i.e. global sharia law and a world-wide caliphate) would require them either to murder or enslave every non-believer on the planet, including every Muslim who doesn't adhere to the cultists' preferred brand of Islam - or to set about gaining power by standing in elections, mending fences with other Muslim sects, and persuading non-believers that all Jews and homosexuals should be put to death, that women are basically worthless, that being poor is groovy, and that being ruled by old, dim-witted, barely-educated religious fanatics is actually a whole heap of fun. 

The problem with the murder and enslavement option is that there are a hell of a lot of infidels on the planet, and we own some seriously impressive weaponry. As for the persuasion - or "working with the grain" - option, most of the world has figured out that life under a global caliphate wouldn't be very nice, what with all the murder, torture and raping, not to mention ignorance and starvation etc. Besides, convincing people is a slow process, and requires a lot of hard work and compromise, and we've learned by now that the favoured islamic fundamentalist approach is being shouty and angry and insulting people and slaughtering them. So, on the whole, your average young Jihadist would prefer to go out with a bang (literally), thereby proving, by committing an act of unimaginable barbarism, how fantastically brave and devout he is (or how brave the women or children he's strapped a suicide-bomb to are)

While condemning right-wingers for having been pretty much spot on about the consequences of porous borders and large-scale Muslim immigration into European liberal democracies, leftists and centrists have been jolly keen to tell us to "carry on as usual", because that's just what the terrorists wouldn't want us to do. Again, I applaud their ability to intuit the secret desires of mass murderers. Normally, I'm all for cocking a snook at psychopathic savages - but only if I believe the government is fulfilling its primary duty to the citizens (or subjects) who voted it into power by doing absolutely everything it can do to keep us safe from harm. Whatever one thinks of Angela Merkel (and I think she has proved herself guilty of what Sir Roger Scruton terms "unscrupulous optimism"), she has not kept her part of the bargain with electors - i.e. not to put them in harm's way. If I were a German, I'd give Christmas markets and public gatherings a miss for the time being, not out of cowardice (they are, after all, most definitely not a cowardly people), but because when your government has done its very best to place you in danger - having ignored and indeed silenced all criticism, no matter how justified - then citizens have a duty to protect themselves and those closest to them, and to keep on doing so until they elect a government more interested in carrying out its duty than indulging in ruinous displays of virtue-signalling.