Turkish democracy has suffered four military coups in the past 48 years; yesterday it came very close to a fifth coup, this time promulgated by the country's Constitutional Court. By one vote, however, the judges held back from outlawing the governing AK party and banning Recep Tayyip Erdogan, the Prime Minister, and dozens of his colleagues from holding political office for five years. The court ruled that the moderately Islamist Justice and Development party had not violated Turkey's staunchly secular Constitution and should not therefore be closed down. It is a notable victory for a popular and capable government, an important judgment on the role of Islam in a modern, secular state and a triumph for Turkish democracy.

It has been a close-run thing. Six of the court's 11 judges, a majority, voted to close the party on the ground that its actions threatened the secular Constitution bequeathed by Kemal Atatürk, modern Turkey's founder. That vote fell one short of the number required. But the court did decide to cut some state aid to the party because it had become a “hub of anti-secular activities”.

The ruling ends months of uncertainty. Reaction was swift. The stock exchange rose sharply, and the currency gained 2 per cent. The AK leadership, which had until this week feared that it would lose, spoke about the vindication of a party that had won 47 per cent of the popular vote at the last election. The European Union expressed relief that the threatened closure, seen as anti-democratic, had been averted and that Turkish negotiations on EU accession would not therefore be affected. Only the powerful and surly military establishment, long seen as the driving force in the attempt to oust AK from power, remained ominously silent.

Mr Erdogan, a wily politician who last year thwarted the army's attempt to block the appointment of his Foreign Minister Abdullah Gül as President, undoubtedly will see the ruling as a vindication of his attempt to rein in the more Islamic elements in his party and present his Government as a normal conservative administration. He may also win further popularity, especially in the Anatolian heartlands, for his courage in standing up to the military. But he has, nevertheless, been checked. The suspicion of many secularists and young urban Turks that the party has been quietly stacking key positions in the bureaucracy and judiciary with sympathisers has been brought out into the open by the court case. Mr Erdogan's attempt to relax the ban on headscarves in university was the trigger that led to the case, and he must now realise the intense controversy that this symbolic move has stirred up. He will need now to move extremely cautiously, aware that there are many within the military establishment who will be smarting at the ruling and looking for a pretext to stage a full coup to remove him from power.

The outcome, however, is hugely important in calming the febrile political atmosphere, reassuring outside investors and underlining the democratic principle in Turkey. Its implications go far wider. It will show moderate Islamists in other countries that Islam is compatible with democracy, and that they should and can work within a secular legal framework to achieve their spiritual ends. That is a message of vital and beneficial significance across the Muslim world.