The 28-nation Nato alliance is proving once again that its founding principal of consensus decision-making can get in the way of reaching agreement on crucial issues. This time it’s over the small matter of who to select as the next secretary-general.

The strongest candidate, Anders Rasmussen, longstanding Danish Prime Minister, favoured by the United States, Britain, France and Germany, is currently being vetoed by Turkey because of his refusal to apologise for the publication in 2006 of cartoons of the Prophet Mohammed in Denmark’s newspapers. The cartoons provoked violent Muslim protests.

The plan at Nato’s 60th anniversary summit which kicks off at a dinner in Baden-Baden tonight, had been to announce the new secretary-general-elect during the meal, congratulate him on his appointment and thank the encumbent, Jaap de Hoop Scheffer, for all his sterling work as he prepares to step down after six years in the job on July 31.

Turkey’s intervention, however, has scuppered the carefully laid plans. The Nato bureaucracy has come up with some other names but none of them, for different reasons, some of them personal, is available or deemed to be politically correct. A Canadian, Pole and Norwegian have been thrown into the ring, but none has met the consensus requirement. One senior alliance diplomatic source said there remained one other option which was to ask Mr de Hoop Scheffer to stay on for a little longer.

Mr Rasmussen, however, is still felt to be the best man for the job, and President Barack Obama, who is to visit Istanbul after the two-day Nato summit, is expected to use all his notable charm to try and persuade the Turks to support his candidature, and to put to one side their concerns about possible Muslim reaction. But the Turks, apparently, are also against the Dane because of suspicions that he supports Kurdish separatists and wants to keep Turkey out of the European Union.

President Obama has other reasons to tread gently with the Turks, because they are due to take on a greater role in Afghanistan. In August a Turkish general is to take command of Nato’s Regional Command Centre which covers the Kabul area.

The Canadian put into the frame, and also supported by Washington, is Peter MacKay, the eminently capable and articulate defence minister. But he has indicated he is keen to stay in his present job, and Nato sources said the European members of the alliance insist the post of secretary-general must go to someone from Europe because that’s the tradition.

Jonas Gahr Stoere, the Norwegian Foreign Minister, has also shown little interest in the job, and the old members of the alliance feel it’s premature to select the secretary-general from one of the new East European members. So that puts paid to Radek Sikorski, the Polish Foreign Minister.

The selection of secretary-general is key to the alliance. Although he or she cannot dictate policy - that’s for the members of the North Atlantic Council - a forceful and persuasive personality with the right level of street credibility with the main alliance leaders can make a big difference.

Some of the past holders of the appointment, such as Lord Robertson of Port Ellen (1999-2003), Javier Solana, the former Spanish Foreign Minister (1995-1999) and Lord Carrington (1984-1988), played an important part in forming Nato strategy at key periods in the history of the alliance.

Times Recommends

• Henning Mankell: ‘If Wallander was alive, I wouldn’t be a friend of his’
• Secret society's skull and crossbones for sale
• Nigerian leader vanishes after medical treatment