Minorities trouble in two main ways: by being a nuisance and by becoming majorities. Doing both in parallel is the greatest threat to the host nation.
Proportionality is the key here: in most places, most people, most of the time, go about their business peaceably. They can rightly say of the troublemakers in their communities that “they are a minority”. True. However, those troublemakers are more frequent in some communities than others, and this is a subtlety that often gets lost in discussion. Troublemakers need some support from their own communities, even if just tacitly turning a blind eye.
The rate at which European communities commit mass murder of their own citizens is very low, though not zero. The US suffered casualties from anti-government bombers. The UK suffered more casualties from Irish Republicans. Basque separatists have bombed Spaniards. However, these dreadful events can be seen as localised grievances, not an over-arching plan.
What troubles most about the Jihadist meme is its generality: its scope is global, and although it has key Western targets, the Crusaders, it takes on all non-believers: white Europeans, Black Nigerians, and anyone else who gets in their way, including brands of Islamic belief they judge to be insufficiently pure.
Like any franchise, it attracts lone entrepreneurs: those who vaguely want to do something, and find a general plan excuse enough to vent anger, disappointment, and general malaise. Insurrections are begun by dreamers and implemented by criminals.
So now we have a dreadful calculus: Western Europe has sizeable Islamic populations, most of whom are not bent on committing murder. Within those populations there are a minority willing to murder on a large scale. Their spectaculars (as the IRA used to boastfully call them) are aimed at showing the population that their governments cannot protect them. They attack the presumption of safety on which civil society is based.
A nation is a protection system, and not a racket if you can leave of your own free will. In exchange for following the rules and paying your dues you get the protection of the state: the protection of borders and the protection of your safety within the boundaries of the state. Insurrections challenge that protection, and taunt both the governed and the government.
The paradox comes thus: any state which guarantees the rights of citizens must also grant them to those who would destroy the state and injure its people. Our interpretation of Magna Carta is that the big letter demands that no-one be arrested without due cause. A noble aim, though of course the original did not apply to all citizens, only to free men, say about 40% of the population at most. It did not contemplate millions of non-Christian non-Europeans, with perhaps 10% of them at least passively in favour of establishing the dominion of another religion and another system of law. That which would have been considered treason is now considered a right which must be defended by the very State which is the target of the attack.
The current European plan, avidly followed in Nice to deal with its sizeable Muslim population (in its own run-down, poor neighbourhood) is to try to spot the militant tendency as early as possible, and bring help, counselling and Police attention to those most likely to commit murder. It may have worked to some extent, but not sufficiently strongly to prevent a large number of volunteers to the global cause going off to do some beheading in Syria, and at least one depressed individual from planning to crush his fellow French citizens to death under the wheels of his truck.
The current plan will continue, I presume, as a careful calculation, that the Muslim minority must not be provoked into turning further against European states, but must be cajoled, convinced, and sometimes bribed to bring information to the Police. Hardest of all will be to explain to Muslims that Muslims in Europe are not poor because Europeans are nasty to them, but mostly because their skills, abilities, and educational achievements, though perhaps a bit higher than in their countries of origin, are not at European levels. European elites baulk at explaining that, and so are caught in a vicious circle of apology. They have assumed that all men are equal, and cannot concede that that is an ideal to which States pay homage (the French particularly, since they count all as Citizens without “noticing” origins) but which does not reflect reality.
So, the plan is for Europe to take casualties, often in very large numbers in very public spectacular executions, and hope that the ideals of the brotherhood of man will win through in the end. In the meantime the pernicious meme will be propagated to all believers: you are urged to kill the infidel by all means possible.
In historical terms, the dilemma is whether it is 1914 or 1939, the former being (according to one school of thought) a time when better diplomacy could have prevented war, the latter being a time when willingness to go to war could have preserved the peace. Perhaps neither war is the appropriate comparison point, and we need to go back as far as the siege of Vienna.