Marginalizing the extremists
As Richard Dawkins observed about Catholics and Protestants in Northern Ireland, for a lot of people in the modern world religion is more a matter of self-labeling than serious belief in dogma. There were actually very few differences in culture between Catholics and Protestants there. The violence in Northern Ireland was the work of relatively small extremist groups (both Catholic and Protestant) who, again, had more in common with each other than with the broad masses of less-fervent people who happened to carry the same religious label as one or the other extremist faction.
The violent extremists are too few in number to win by themselves. Their only hope of achieving their goals is to radicalize the masses of normal people who carry the same religious label as themselves. Their preferred method for this is preaching and exhortation, but that rarely has much impact except on the already-persuaded. More effective is creating an atmosphere of paranoia and panic in which all those who do not share the same label are demonized as dangerous aliens, drawing a hard-and-fast line around one's own group and creating a feeling of being under siege by a vast horde of outsiders. When large numbers of people view the world that way, the extremists are winning.
Violence is a preferred tactic for achieving this situation. It, and the responses it tends to provoke, help extremists in both label-camps to achieve the paranoid state-of-siege feeling they are both after. For example, jihadist terrorist attacks such as the one in Paris encourage such feelings in Westerners and especially in the kind of fervent Christians who already tend to see the world through a "clash of civilizations" model, with Christianity and Islam implacably opposed to each other. When politicians from this group then start talking about stigmatizing Muslims in the US with special ID cards or accepting only Christian refugees from Syria, vast numbers of non-extremist Muslims -- including some in the US -- feel targeted and, perhaps, become more open to the idea that the West really is against them all and that the jihadists have a point. This state-of-siege feeling, of course, is exactly what the jihadists want.
Violence targeting Muslims is also happening, though it tends to get less publicity because it usually takes the form of many smaller-scale attacks rather than a few large terrorist operations. Examples include not only the mosque arson in Peterborough but such incidents as this gunfire attack on a house in Florida or this shooting of a taxi driver in Pittsburgh. No one had any reason to think the targets in these cases were dangerous, any more than the random civilians targeted in Paris were dangerous to anyone. They were targeted because they were members of an out-group whose very presence is unacceptable to the extremists. The same is true of the even more dangerous efforts of fundamentalist politicians in the US to target Muslims for discrimination and to impose Christian taboos on the secular majority by enacting them into civil law.
To fight back against extremists, we must reject at every turn the paranoia and siege mentality they are trying to create, and we must insist on a different, accurate analysis of the conflict to defeat the "clash of civilizations" model they are trying to foist on us. That accurate analysis is that this is a war of extremists, both Muslim and Christian, against normal people whether Muslim, Christian, or non-religious.
The jihadists who attacked the Bataclan theater and the religious nut who attacked the Planned Parenthood site in Colorado Springs were not consciously collaborating, but they were the same kind of people doing the same kinds of things to the same kinds of targets for the same kinds of reasons. Ultimately all religious extremists are lashing out at a secularizing world which is leaving their taboo systems behind (note that some Christian extremists in the US reviled the victims both of the Planned Parenthood attack and of the Paris jihadists). But because they are few in number, their ability to do real damage to our world depends on dividing us against each other on the basis of their religious labels.
Fortunately plenty of peaceful people are aware of this and are taking active, even risky, action to counter it. Almost five years ago I noted this incident in Alexandria, Egypt, where Muslims turned out to act as human shields at a Christian church after a wave of jihadist attacks on Christians. The Obama administration's response to Dâ'ish (ISIL) -- targeting the extremists with airstrikes and taking a back seat to the Arab and Kurdish forces fighting against them, rather than the massive indiscriminate violence and wars against entire countries which many Republican politicians favor -- shows the same wisdom. Our goal must be to marginalize the extremists, to isolate them, to collaborate with other sane people against them, and eventually to destroy them.