If you ever drive past a British Ministry of Defence establishment, then your attention may be caught by some of the things going on behind the wire fence. Now, let's get this straight; we're not suggesting you stop and stare: signs attached to the fence prohibit photography, and if the Mod Plod¹ catch you, they will as likely round you up and treat you to a little light waterboarding. But, out of the corner of your eye, maybe amongst the rusting Nissen huts, you might spot a few golf-ball shaped structures in a field, say, or a small group of white-coated boffins staring at them while making notes on their clipboards. If you're particularly observant, however, you may spot a sign on a wall near the site's main entrance. It bears the title 'Bikini Alert'.

Intrigued? You might even be tempted to set up your folding chair and inspect the clothing of all the MoD personnel entering and leaving the site, but you would be disappointed. Even the Rear-Admiral's greatcoat doesn't hide the garment that you might have been looking for². For 'Bikini' is none other than a code name for the security alert system.

Bikini Colours

The Bikini code is specifically used to classify terrorist threats - other military threats will have different code names. The alert state is indicated by one of a number of colours, depending on how serious, specific and imminent the threat is:

• Bikini White is the lowest level. There is no known threat.

• Bikini Black means that there is a possibility of a terrorist attack, but it could occur anywhere at any time.

• Bikini Black Special³ is a heightened version of Bikini Black. Specific intelligence shows that a terrorist attack is more likely.

• Bikini Amber states that there is a known threat to an unknown Government target within a specific period of time.

• Bikini Red means that a known threat to a specific target is imminent.

A couple of points are worth mentioning here. First, you will be unlikely to casually spot Bikini Amber or Red when you're passing a military site; the MoD Police will step up security according to the alert state, and might well close access roads or search vehicles. Second, when they do arrive, the terrorists themselves will not be wearing bikinis - that only happens in Bond movies.

The UK Government doesn't divulge the current Bikini alert colour, but in these times of heightened terrorist activity, you would expect it to have been Bikini Black Special at the very least since the 9/11 terrorist attacks and other Al Qaeda-inspired attacks in the UK. Prior to this, it would have been at a heightened state at times during the IRA's bombing campaign on the UK mainland. Indeed, it is known to have been at Bikini Red for a period following the death of the imprisoned hunger striker Bobby Sands in 1981.

Civilian Alert States

The Bikini system isn't used in the civilian world, but something very similar is. Through its Joint Terrorism Analysis Centre the UK Government issues a 'threat level', which again can take one of five states:

• Low - an attack is unlikely.

• Moderate - an attack is possible, but not likely.

• Substantial - an attack is a strong possibility.

• Severe - an attack is highly likely.

• Critical - an attack is expected imminently.

As you can see, these are very similar to the Bikini alert states, but the Government prefers to retain the separate system for Government offices and MoD sites. In 2003 when asked why, their response was:

The system we have in government buildings for colour-coding has very specific meanings which are understood by the security staff and by those who work in those buildings so that if that alert state changes, then everybody knows exactly what to do, and that is in the confines of a single building.
– Sir David Omand (head of security and intelligence at the Cabinet Office)

So now you know.

So why 'Bikini'?

Now, the military are very clever at code names. Their attempt to hide the true identity of a secret project to develop an all-terrain armoured vehicle was so successful that we still know the invention today as a 'tank'. Maybe they thought nobody would notice 'bikini' either.

It would be great to link this word to the skimpy beachwear, but that's simply not the case. Neither is the word anything to do with the Bikini Atoll in the Marshall Islands in the Pacific, where the US tested nuclear weapons in 1946 and 1954.

All the UK Government has ever admitted when pressed on this subject is that the word was chosen at random, using a computer.

What's the Bikini Colour Now?

It's best you don't ask these things. If we told you, then we'd have to shoot you.