Sarkozy has struck at the heart of Europe's liberty

The "burqa ban" now in force on the streets of France is as illogical as it is ill-conceived

It began yesterday. In a nation of 64 million people, in a country recovering from a global financial crisis, in a state facing serious problems of crime and poverty, of sexual assaults, drug-dealing and prostitution, the weight of French law will now fall on the heads of just a few hundred women, in what is surely one of the least widely-applicable laws the Fifth Republic has ever passed.

What has been dubbed the "burqa ban" is now in force on the streets of France, specifying that French citizens cannot cover their faces in public places. In reality, the law is as ill-conceived as its nickname: the item of clothing the lawmakers are targeting is actually the niqab, the head covering that reveals the eyes rather than the complete covering cloth mostly worn in Afghanistan.

Not one of the problems listed above will be solved by banning this piece of cloth - and indeed not one discrete problem has been identified that will be solved by the law.

But that's not the fatal flaw in this politically-driven decision; the flaw is that in practice and in principle, it doesn't work. In trying to twist French principles for his political ends, Nicolas Sarkozy has struck a blow at the heart of Europe's liberty.

As much as the ban is politically motivated, the logic of it - the logic that its supporters have spent much intellectual energy defending - is flawed. There is little evidence that the adult women who wear the niqab have been coerced into doing so - and, in any case, the law applies to so few women that, were the ban to be seen as a feminist measure to empower French women, there are other more productive targets at which the lawmakers could have taken aim.

Worse, if women were coerced into wearing the niqab by their families or husbands, the ban does not empower them: the most likely outcome is that they will simply stop going out. Indeed, as I've argued before, men who dictate the clothing of their wives are likely to dictate much else and the small pressure relieved in one area is likely to be more than compensated elsewhere. Closing off public space to citizens is not empowering.

As a measure of integration, the law is hardly useful: the chief problem France's minority groups face is a lack of opportunities, not their faith. As a security measure, it is almost worthless: any "burqa bomber" (of which there have so far been precisely none in France) only has to dress as or claim to be a tourist to circumvent the law, which only applies to French citizens. And while a flowing burqa might well be a good place to conceal a weapon, it makes escape problematic, especially on a motorbike. Armed robbers who used stockings for years were hardly queuing up to be fitted for a niqab. This is a non-argument.

Nor will the law be easily enforced. Take the thousands of Arab tourists who go to France every year, add the number of euros they spend in Parisian luxury shops, factor in that London is only a couple of hours away if those tourists feel harassed, and it is fairly clear that if this law were applied strictly it is the Parisian economy that would suffer.

If the practice is flawed, so is the principle. Leave aside the notion that people's devotion or their political beliefs can be changed by their clothing. (When in reality it is far more likely they will feel excluded from their country and its public spaces.) It is dangerous for open societies to allow the state to dictate what they can and can't do in their private lives. The principle at stake is so serious, I struggle to see how the French have missed it: the idea that the state should dictate people's clothing, beyond the literal and metaphorical bare minimum, is violative.

There may be grounds for arguing that clothing carries cultural - even political - meaning. But those meanings are often disputed and are heavily dependent on context. Indeed, one of the reasons to argue for the principle is that the interpretation of the veil is so mixed. When some people look at the veil, they see in it a symbol of women's oppression. They say that the veil is a way of obscuring women's involvement in a society, of considering her sexuality to be so dangerous it must be hidden.

But equally there are people who look at the veil as a means of liberation, releasing them from being judged on their appearance, or as a mark of their devotion and humility. These interpretations are passionately defended.

It is precisely because it is difficult to decide between those two conflicting views (as well as others) of the veil, that the principle needs to be upheld. And the principle is one of choice: in a liberal society, the state has no business interfering in what people wear in their private lives.

The English poet John Scott of Amwell once wrote that the drumbeat of war too often lured people to "sell their liberty for charms of tawdry lace". Alas, for France, the dreary drumbeat of politics should lure politicians to sell their liberty for the thin weight of a veil.