Leading article: Collision course in Turkey

It is hard to think of a nation more familiar than Turkey with the tensions between East and West, between religion and nationalism, between autocracy and democracy. But those opposing forces seem to be reaching a new intensity of late. The ruling Islamic party is at risk of being outlawed by the Constitutional Court. Another court is hearing a case against a collection of ex-army officers accused of plotting to overthrow the government by force.

But this battle for Turkey's soul is not merely taking place in court rooms. There is blood on the streets too. Two bombs exploded in Istanbul yesterday, killing 17 people. The main suspects are Kurdish separatists. The country's stock markets have taken a battering as investors grow nervous about the future direction of the country. A sense of crisis is building.

The irony is that the governing AK Party, despite its roots in the Islamist movement, has done a good job of contradicting the popular notion that political Islam can never settle within a secular and democratic state. Under the leadership of the Prime Minister Recep Tayyip Erdogan, the AK Party won a hefty mandate from the Turkish people in fair elections last year. It has pursued liberal economic policies and pluralist social policies. No one disputes that the AK Party enjoys broad democratic consent.

What it lacks is the consent of the fiercely secular governing classes and the military. This is the background to the attempt by the Turkish chief prosecutor to have the AK Party banned on the grounds that it is attempting to subvert Turkey's secular constitution.

The case might be regarded as being, in one respect, commendable. It shows that the Turkish government is subject to the rule of law. But it is also hard to avoid the conclusion that the secularists have overplayed their hand. The moves by the AK Party to lift the ban on female students wearing headscarves do not add up to a secret plot to Islamise the state.

Of course, Turkey is not the only nation to face a constitutional crisis, the threat of a coup, or a separatist insurgency. But Turkey is globally pivotal in a number of ways – and it matters. Most obviously, it matters to the future of the Middle East. Military incursions into the Kurdish-ruled north of Iraq threaten to plunge that country into fresh turmoil. A democratic government is far less likely than a military junta to embark on an invasion of its south-eastern neighbour. Turkey also matters to Europe. Much is rightly made of the potential prize of incorporating this fast-growing economy into the EU. And just as valuable is the leverage the possibility of entry offers to progressive politicians within the country. If Turkey is to emerge from this crisis as a stable and democratic nation, it will need all the help its friends can muster.