President Vladimir Putin belatedly recognised the scale of Russians' distress and anger over thesubmarine tragedy when he confessed to a "total sense of responsibility and sense of guilt" in a speech 11 days after the accident.

Those who accused him of callous indifference in the days immediately following the disaster, when he failed to break off a holiday on the Black Sea, were rewarded with an account of the president's own personal pain when he spoke to the nation in a televised address.

"It is difficult to pick the right words. It makes you want to howl," he said, apparently referring to an emotional meeting with relatives of the dead sailors at the northern fleet's headquarters.

Witnesses of this meeting said Mr Putin calmed a hostile audience with plain talking, sympathy and evident emotion.

Indifference

It was the first time he had been seen dressed in black.

His only earlier effort to capture the national mood of impending tragedy - more than a week after the submarine sank - was woefully inadequate.

"We are all following the tragedy now unfolding in the Barents Sea with aching hearts, and without any exaggeration, with tears in our eyes," he said on Sunday.

But there were no tears in Mr Putin's eyes, and nothing to erase the image of the tanned president in his shirtsleeves, relaxing on the Black Sea coast in the first days after the Kursk crisis broke.

In principle he is a very emotional man, but he was completely incapable of expressing his emotions

Sergei Raldugin

Mr Putin appears to have been caught in a public relations trap. His political success has been built on his image as a virile man of action - an image which he may have felt would have been undermined by a public display of feeling.

Instead, his failure to become engaged - and in particular his failure to return to Moscow until last Friday, six days after the Kursk sank - was widely interpreted as lack of concern.

But it's also likely that Mr Putin's own personality makes it difficult for him to express his feelings in public.

In the collection of interviews with Mr Putin, his family and friends, which was published shortly before the Russian presidential election in March - and which remains the best key to his personality - one friend explained how difficult the career KGB officer found it to express emotion.

Too calm

"In principle he is a very emotional man, but he was completely incapable of expressing his emotions," said Sergei Raldugin, a cellist at St Petersburg's Mariinsky Theatre, recalling Mr Putin's first serious relationship with a woman, which began during his student days.

Putin's twists and turns

12 Aug: Goes on holiday hours after sub sinks 14 Aug: Receives report from Navy chief 16 Aug: Makes first comment on disaster, and orders navy to accept foreign help 17 Aug: Putin should end holiday say 73% of callers to a Moscow radio station 18 Aug: Finally returns to Moscow 20 Aug: Says his heart aches 22 Aug: Flies to Murmansk and meets relatives as poll shows 8% drop in popularity 23 Aug: Accepts responsibility

"I used to say to him: 'Vovka, it's frightening talking to you.'... He had powerful emotions but he could not put them into words.

"I suspect his job influenced the way he talked, his speech became a series of cliches."

Mr Raldugin added that he thought Mr Putin had now become a brilliant speaker - "emotional, deep, clear" - a judgement that the last few days call into question.

In the same collection of interviews, Mr Putin was asked if he was calm under stress. He replied that the KGB had told him he was much too calm.

"Apparently you are supposed to be wound up when you're under stress, in order to respond appropriately. It is considered important," he said.

Naval family

Mr Putin's wife, Lyudmila, also gave the authors of the book an insight into Mr Putin's analysis of his own character.

Immediately before proposing to her, she said, he acknowledged that he was taciturn, as well as sharp-tongued and capable of causing offence.

Mr Putin does, however, have a naval connection. which may have made it easier for him to express sympathy with the bereaved relatives he met in Murmansk.

He was brought up in St Petersburg, a major Russian port.

His uncle was a naval officer, and his father served on a submarine in in the 1930s.

At an early age, before fixing his sights on a career as a KGB spy, it was his ambition to became a sailor.