WHY DOESN'T BLAIR JUST SAY SORRY, IT WON'T HAPPEN AGAIN?

Just get them back, and sort out the legal stuff after.

Is he prepared to see the arrested servicemen and woman swing from a crane or lamppost to get his bloody war?

I think so. Otherwise he would have said so already.

I think he will try an attempt at compromise but by then it will be too late and Iran will have got itself into a position from which it cannot escape without appearing to look weak.

But let's remember what has happened before this.

BP was The Anglo-Iranian Oil Company and had control over Iran's oil.
When the Iranian Mossadegh was voted in by the Iranians and wanted to use the profits from Iranian oil for Iran and the Iranians he was ousted by the Anglo-American Intelligence apparatus, and was replaced by a puppet Shah who brutally repressed Iran with the Anglo-American trained SAVAK.
During his reign the USA began to sell Iran the technology for nuclear power.
But when that puppet Shah began to show signs of using the profits of Iranian oil for Iran and the Iranians he was ousted in the 1979 Iranian Revolution which replaced that puppet Shah with a man with British roots whose father worked for BP, Ayatollah Khomeini, during which around 50 hostages were held captive in the US Embassy. It is believed that George HW Bush flew to Paris to meet with the Iranians to ask them to hold the hostages until AFTER the US presidential election that year in return for money and arms, to make Jimmy Carter look weak. Carter lost and Bush became VP to Reagan.
When Bush's son became President George Jr labelled Iran a member of "The Axis of Evil".

The USA has since arrested/abducted a number of Iranians, notably some from Irbil, and made it open season for the US Military to shoot any Iranian. Before then there was Abu Ghraib and the photographs of torture. Then there was the Prophet Mohammed cartoons, which caused Iran to run a cartoon competition of its own, and the winning cartoon is below.

And despite all this action which has caused great mistrust in Great Britain and the USA, and in what I believe to be a deliberate provocation, HMS Cornwall left two dinghy boats to dangle in front of six Iranian boats in disputed waters and was told to do nothing while the dinghys and their crew were dragged to Iran, so that Blair could claim the moral high ground claiming the boats were captured in Iraqi territorial waters without any legal grounds to back him up.

Here is the winner of the Iran Cartoon Competition from last year.