Londoners have not taken kindly to the idea that their city was shaken by last weekend's terror attack. Ordinary people tweeted their disdain for ISIL, but more specifically for the idea an attack could change their way of life. The city “will never be cowed”, said London’s mayor, Sadiq Khan.
Analysts, too, have pointed out that the UK has faced much worse. Throughout the 1970s and 1980s, Britain suffered far more terrorist attacks at the hands of the IRA, with far greater loss of life.
That's true, of course, but it misses a crucial aspect: an entire generation has grown up without any real knowledge of life under terrorist attack. In Britain, the worst of the Troubles were much worse than the current threat from Islamist terrorism – but millions of Britons are too young to remember the IRA's bombs and the fear on London's streets. This is a new experience and most are simply unwilling to accept that the current situation will become a new normal.
That is a serious political challenge for the UK. Because ISIL's sectarian strategy, used to great effect in the Middle East, is being imported into Europe. And the wrong political choices will walk the UK directly into the jaws of a trap set by ISIL.
ISIL prefers to pose as protectors. Their sectarian strategy in Iraq was to pose as protectors of the Sunni population against the sectarian policies of a Shia-led government. In Europe, they want to do the same, splitting Muslim communities from the general population, so that they turn to ISIL for protection – and, even better, leave to populate their “caliphate”.
In jihadist circles, this is called the strategy of the “grey zone”. By attacking European cities, ISIL hopes to provoke a backlash against Muslim communities in Europe – forcing them to choose between European governments (who may be enacting oppressive measures against them) and ISIL.
And it could just work. Not only because of the way people react to terror attacks, but because of wider issues in Europe. As so often with political tectonic shifts, there are other major political forces acting simultaneously.
Russia is also seeking the destabilisation of Europe. There are suspicions that Russia has supported anti-European parties such as Britain’s Ukip and France’s National Front – certainly Russia's English-language media has given their views a platform. Just last week, intelligence reports demonstrated that Russian spies have been provoking discord in Balkan countries.
The result is that European countries are internally divided, unable to agree a common front. Islamist extremist groups thrive in that environment – the fragmentation helps their central argument, that Muslims cannot be safe anywhere but under their "caliphate".
This strategy is not limited to ISIL. The way to understand the current threat of Islamist extremism is to see it as a set of ideas, akin to communism, which is currently spearheaded by one particular group, in this case ISIL. But just as the mantle of leadership of violent Islamism passed from Al Qaeda to ISIL, so it could pass again. If ISIL are sufficiently degraded in Syria and Iraq, they could vanish as a cohesive force. In their place, a new group could emerge, or the leadership could pass to another group, such as AQAP in Yemen or Boko Haram in West Africa.
Just as with political parties, once their popularity wanes, so their funders and supporters will go elsewhere. ISIL's strategy is fundamentally a political strategy – by dividing European communities, it hopes to secure its long-term status as a political force.
Contrary to the debate in the UK about foreign policy as a motivator of these crimes – which, while it has some merits, is not the whole story – ISIL is choosing its attacks based on where it thinks it can gain the most recruits.
The two European countries that ISIL has hit hardest are Turkey and France, both places with significant Muslim populations who could be drawn into the conflict. The recent attacks in the UK were certainly designed to influence this week's general election, but ISIL clearly feel there is a chance that Britain's Muslim communities can be cleaved from the broader population.
It will be up to politicians to prove them wrong. And that's where things get tricky. Because politicians prefer to respond to public pressure with concrete policy proposals. “Solidarity”, “community cohesion”, keeping calm and carrying on – these are not policy proposals.
When the angry voices of the public are harnessed by the media, the chorus becomes too loud for politicians to ignore. That is the point of danger and the point of leadership, the moment when political choices can make the situation worse. With the rhetoric already rising from 10 Downing Street, and a public seeking solutions, politicians could easily tiptoe towards ISIL's trap.
On Twitter: @FaisalAlYafai