Leading article: No decent law allows coercion

"You can barely use the word sharia because of what people associate with it." How right Rowan Williams, the Archbishop of Canterbury, turned out to be. The idea of finding "a constructive accommodation with some aspects of Muslim law", of which he spoke in a BBC Radio 4 interview last week, is one that triggered a reaction not wholly related to his actual words. But if he knew that sharia was a word susceptible to misunderstanding, surely he should have known how important it was for him to be clear.

It was no use Dr Williams protesting that he was not talking about the "brutal and inhuman and unjust" forms of sharia as practised in Saudi Arabia or countries where women are stoned for adultery if they are raped. The problem is that, even if we take out the stoning, the chopping off of hands and the "honour" killing, a code of law that claims its authority from long-standing religious tradition is likely to be reactionary in general and restrictive of the rights of women in particular. Dr Williams acknowledged at one point in his lecture that "questions of the status of women and converts" in sharia were "neuralgic". But if he were not talking about that kind of sharia, it was unclear what he was saying.

Thus he allowed many people to read a subtext to his words, which is that there is "one law for us and another law for them". It is a widespread sentiment, tinged with racism, and anyone in a position of leadership ought to be careful not to provide unwarranted support for it.

Nor is it any use Dr Williams's supporters – or, more accurately, those people of goodwill who sought to understand what it was that the Archbishop might have been trying to say – pointing out that some religious courts are allowed to arbitrate on questions of marriage among orthodox Jews. The point is that no special amendment has been made to UK law to allow these courts to function. There can be no objection in principle to religious authorities that set themselves up as arbitration or mediation services; the question is whether their clients take part on the basis of informed consent.

Indeed, as the Archbishop said in his interview: "It would be quite wrong to say that we could ever license a system of law for some community which gave people no right of appeal, no way of exercising the rights that are guaranteed to them as citizens." That would seem to go to the heart of the issue. The worry about religious courts – Jewish or Muslim – is that they resist equal rights for women, and it is difficult to define where voluntary submission by women ends and coercion begins. Instead of proposing further "accommodation" of religious law, we should be more robust in policing that boundary.

This is the same issue in forced marriages, which, as we reveal today, have been massively under-reported in this country. The scandal of "honour" killings is the visible extreme end of a subculture which oppresses women, and which draws on the authority of religion, as Joan Smith points out today. This situation has come about partly because of a well-meaning attempt to accommodate the cultures of immigrants, of which Dr Williams's lecture seems to be a part. Recently, significant liberal voices, such as that of Trevor Phillips, chairman of the Equality and Human Rights Commission, have insisted that there must be limits to this ill-defined multiculturalism. What was remarkable about the Archbishop's intervention was that he did not engage in this argument at all.

So let us do it for him. The law in a liberal democracy should apply to everyone equally, as far as possible, with exceptions in only the most difficult cases for conscientious objectors. That includes Sikhs riding motorcycles, or doctors who refuse to carry out abortions. It should not include turning a blind eye to forced marriages, or to the use of arranged marriages as an immigration scam; nor should it include paying state benefit to multiple wives.

In each case, the current of thinking, even among liberals and among liberal British Muslims, is away from the direction suggested so nebulously by Dr Williams. The Association of Chief Police Officers is taking "honour" killing and forced marriages more seriously than ever. Ann Cryer, the left-wing MP for Keighley, has been harrying a government that appears to lack any sense of urgency over arranged marriages that amount to a form of people-trafficking from Pakistan.

On every issue where there is tension between religion and state, the Government needs to be encouraged by defenders of liberal democracy to insist on the primacy of universal rights. The Archbishop was well-intentioned but unwise to allow himself to be allied to the pre-Enlightenment elements of another faith by trying to go in the opposite direction.