David Cameron learns about war the hard way

That Colonel Gaddafi is proving more difficult to dislodge than the politicians and military men supposed goes without saying. The interesting question is why, given our disastrous experiences in Iraq and Afghanistan, a British prime minister should want to initiate armed conflict abroad.

David Cameron might be inexperienced and he might not have won an election, but surely the one thing he wasn't going to do was start a war.

The fact is that once installed in the imperial nostalgia of Downing Street some prime ministers just can't help it. The first few hours for a new incumbent back from kissing hands at Buckingham Palace are extraordinarily exciting and seductive.

Forget about the NHS and the railways and the deficit. The grandeur of Britain's secret state is on display.  Once through that famous front door, Cameron like his predecessors was ushered into the Cabinet Room for a number of urgent briefings.

A portrait of Winston Churchill, imperial soldier, statesman, warlord and the greatest of all British prime ministers gazes benevolently down on his successor sitting exactly where he sat when taking the great decisions of the Second World War.

The first task for a rookie prime minister is to compose Nelsonian handwritten and sealed orders to the captains of the Royal Navy's 'Black Bombers' ­ the submarines which carry the country's Trident nuclear deterrent.

Next on the agenda are the intelligence agencies. There is little pleasure to be had from MI5's briefers. The sordid and grinding details of domestic jihadism and resurgent Irish Republican terrorism are more likely to alarm than exhilarate.   
 
But that's not the case with the silky smooth men and women from the Secret Intelligence Service, MI6. Actually, they aren't just a service ­ more of an international brand. Dame Shirley Bassey won't be on hand to sing Diamonds are Forever as they troop into the meeting and they won't be wearing dinner jackets. But there is never any doubt that they belong to the same organisation as James Bond.

Add to this GCHQ's mind-boggling ability to intercept communications and any new prime minister gets a sense of a Rolls Royce intelligence machine at his disposal. If a problem occurs, these people will know what to do and they answer not to parliament or the press but to the prime minister alone. It's a seductive package.

Those giving the briefings believe in the power of intelligence or secret information to change the world. Sadly it's not as simple as that.

Intelligence at its best can send a British prime minister into negotiations with a foreign leader knowing both his adversary's bottom line and something of his character and weaknesses. It's a bit like cheating at bridge.

But there are limitations. The most it can do is gain an advantage. It is rarely decisive. You must play your hand well for it to work. Even when the intelligence is near perfect it cannot make up for a bad plan or plain bad luck.  

The most famous example of this in British history is the May 1941 invasion of Crete by German paratroopers. Codebreakers at Bletchley Park gave Churchill and his chiefs of staff two weeks' notice of the attack, including the precise drop zones for the assault ­ all passed on in detail to the British and Commonwealth garrison. They fought bravely under an experienced general with a Victoria Cross and outnumbered the Germans by two to one - but still lost. The Germans were just better.

It is clear from the botched MI6 mission to Benghazi on March 6 that senior members of the intelligence and security establishment have been keen from the start on intervention in Libya.

As if their siren voices were not seductive enough, another group has been influential in encouraging Cameron's decision to attack Libya ­ the proponents of air power. The air marshals' message never changes, ­ bombing will work this time round, we promise. You don't need tanks and infantry. We can do this from the air.

It didn't work for Bomber Harris against the Germans and it won't work for his successors against Gaddafi's Libya. As poor old David Cameron must be beginning to realise while on holiday in Spain - the only reliable way to defeat someone's army is with another army of your own.

And it gets worse. Whatever the outcome in Libya, the recent Strategic Defence and Security Review, which was meant to set priorities for defence over the next generation, will almost certainly have to be reconsidered. At a time when the country is trying to balance its books, Cameron¹s poor judgment and naivete are proving expensive indeed. ·