The release of the 24 members of the US military held by China may well have been assured by a single word - sorry.

It is one that the Bush administration appeared reluctant to even contemplate.

But 11 days into the stand-off, the US said in a letter to China it was "very sorry" for the loss of a Chinese fighter pilot in a collision with a US spy plane, and for the US aircraft's entering Chinese airspace without permission.

We are very sorry the entering of China's airspace and the landing did not have verbal clearance

US letter to China

Chinese President Jiang Zemin had demanded a full apology for the mid-air collision.

But while the US expressed "regret", it said it had done nothing wrong, so would not apologise.

Like two quarrelling children, the superpowers had appeared to have reached an impasse that could only be defused by language.

As regional tension mounted, both countries came under pressure to find a form of words that would be mutually acceptable.

What's in a word?

But this meant navigating the dangerous waters of national pride, different social values, and language loaded with cultural sensitivities.

Definition of sorry:

1. feeling distress, especially through sympathy with someone else's misfortune 2. feeling regret or penitence, used to express apology

Concise Oxford dictionary

In Mandarin Chinese - as in English - there are numerous ways of apologising, each with their own shades of meaning.

The Chinese demanded a formal apology - or "daoqian" - which carries with it an admission of responsibility and expression of remorse.

An apology using the word "daoquian" allows the injured party to save face, which has enormous importance in Chinese society.

Earlier US expressions of regret were translated using the word "yihan", a term that carries no acknowledgement of guilt.

The Chinese language copy of the statement eventually issued said President Bush expressed "shen biao qian yi" (sincere regret) for the missing pilot, and was "zhen cheng yi han" (very sorry) for the unauthorised landing.

Both are ambiguous expressions which may or may not carry implications of blame.

Belgrade apology

In the US, saying sorry also carries with it the connotation of accepting blame.

I regret that a Chinese pilot is missing and I regret one of their airplanes is lost

President Bush

And in a deeply litigious society, this is something that many Americans may be instinctively wary of doing - unless they are trying to argue that something was an accident rather than deliberate.

Two years ago when the US bombed the Chinese embassy in Belgrade, President Clinton managed to defuse the tension by making a public apology.

"I have already expressed our apology and our condolences to President Jiang and to the Chinese people, and I have confirmed our commitment to strengthen our relationship with China.

"I apologise. I regret this. But I think it's very important to draw a clear distinction between a tragic mistake and a deliberate act of ethnic cleansing," he said.

A question of blame

Crucially, this time the Bush administration did not want to accept the blame.

But as the incident dragged on, public statements of regret became progressively more conciliatory in tone.

"We have expressed regrets, we've expressed our sorrow, and we are sorry that a life was lost," Secretary of State General Colin Powell said a week after the crash.

American planes come to the edge of our country and they don't say 'excuse me' - this sort of conduct is not acceptable in any country

President Jiang

Although still not an apology, this was in marked contrast to previous statements which did not use the word "sorry".

"We regret the loss of life of that Chinese pilot, but now we need to move on," he said earlier in the week.

President Bush also said he "regretted" that a Chinese pilot is missing and that one of their planes has been lost.

The deadlock was eventually ended on 11 April by a letter to China from US Ambassador Joseph Prueher on behalf of his government.

"Both President Bush and Secretary of State Powell have expressed their sincere regret over your missing pilot and aircraft," the letter said. "Please convey to the Chinese people and to the family of pilot Wang Wei that we are very sorry for their loss ...

"We are very sorry the entering of China's airspace and the landing did not have verbal clearance."

It may not have been the full apology demanded by China, but at the least it was a way of reaching a compromise that involved translating a US expression of regret in a slightly different way in Chinese.