My first point of reference for this film was the excellent "Who Dares Wins", with Lewis Collins, which was inspired by the Iranian embassy rescue and shows the SAS at work, culminating in a very similar (fictional) hostage event. But having watched "6 Days" I see it more in the light of the very good "Eye In The Sky", showing just how much thinking and planning goes on behind the scenes of real life military action and crisis response, including the unexpected details that can derail even meticulous planning.
The political situation was highly complex as this was the embassy of the awful Khomeini regime and the invaders were protesting the crimes of that regime back in Iran. Nevertheless, they took terrorist action and violated the diplomatic privilege that embassies around the world enjoy. And in responding to it the UK would have to violate the diplomatic immunity all foreign embassies are entitled to. In that respect, violating the immunity of the US embassy in Iran had set a precedent (as did GDubya's later invasion of Iraq), so it's a useful reminder of the potential consequences of trashing the norms of civilized behaviour.
A hostage situation is always tense, but especially so when dealing with a heavily armed group that is not afaid to die (indeed many fanatics welcome it) and insist on all their demands being met or they will kill their hostages. There was also the disastrous precedent of the German attempt to free the Munich Olympic hostages, which further constrained the UK action. And of course the ticking clock is always a key factor.
And so the film offers us insights into what went on, in the negotiations, behind the scenes and in the eventual rescue - where the odds were clearly stacked in the terrorists' favour and yet was conducted without loss. That's an achievement that is worth preserving on film!
