What's in a name?

If it weren't so tragic, it would be laughable. Within a week of 30 British holidaymakers being shot dead in Tunisia, David Cameron is complaining about the name by which the BBC refers to the group that is alleged to have been behind the attack.

Islamic State, he says, is neither Islamic nor a State. He's right -- on the other hand, nor was the Irish Republican Army ever an army. So what? A name is no more than what someone chooses to be called. Does he really think that a single one of IS's recruits was attracted to its ranks because they were misled by its name?

I wish the prime minister could be persuaded to focus on what's important, rather than taking easy pot shots at the nearest available target. (There's a well-established golden rule for all governments, of any political complexion: when you don't know what to do next, attack the BBC.)

I have not the slightest doubt that those who profess loyalty to IS and others who think like them do pose a serious security threat to Britain and to British citizens. (As if we needed reminding, next week will mark the 10th anniversary of the London bombings, when four suicide bombers killed 52 people and wounded several hundred more.)

So what should Mr Cameron be focusing on? Well, a good start -- given that last week's attacks took place in Tunisia -- might be to offer more help to the government of that country, which is just about the only (relative) success story to emerge from the chaos of the 2011 Arab uprisings. What that means is help with boosting its security forces without toppling back over the edge into dictatorship, and help with social and economic reforms, to give young Tunisians more to hope for than martyrdom.

As Claire Spencer of the Royal Institute of International Affairs wrote in the Financial Times yesterday: "In the small towns of the Tunisian interior such as the one where [the Sousse gunman] Seifeddine Rezgui grew up, young jobseekers face even gloomier prospects now than they did in December 2010," before the start of the ill-named Arab Spring.

Mr Cameron should also be rethinking his absurdly indulgent attitude towards the Egyptian military coup leader Abdel Fattah el-Sisi, who seems to be doing everything he can to inflame a new Islamist revolt in the Arab world's most populous nation. You probably missed it, but just a couple of days ago 100 people were reported to have been killed in a clash beween Islamic State fighters and the Egyptian military in the Sinai peninsula. In Cairo, nine members of the banned Muslim Brotherhood, including a former MP, were killed in a police raid.

And while he's at it, the prime minister might consider digging out the triumphalist speech about Britain's military intervention in Libya that he made in the House of Commons in September 2011: "Removing [General Muammar] Gaddafi from power was a major achievement ... Although the work is not yet done, the Libyan people can be proud of what they have achieved and we can be proud of what we have done to help them."

In that same speech, he also said: "The long work of building a new Libya is just beginning. But what is clear is that the future of Libya belongs to its people ... The task of the international community now is to support them as they build that future ... So let me be clear. We will not let up until the job is done."

How hollow those words sound today. Why is it, I wonder, that when you mention the words George W Bush or Tony Blair, people immediately think of Iraq -- but when you say the words David Cameron, no one says Libya? The gunman who slaughtered those 30 British holidaymakers in Tunisia was apparently trained across the border in Libya, where anarchy has taken hold since the overthrow of Gaddafi and where IS seem to be going from strength to strength.

Britain played a leading role in the international military operation that enabled Libyan rebels to topple Gaddafi, and Britain has done little or nothing since then to stop Libya sliding into chaos. This is a hard thing to say, but it may well be that if Mr Cameron had made a different judgement call in 2011, the holidaymakers killed in Sousse would not have lost their lives.

Nor might some of the nearly 2,000 migrants who have drowned in the Mediterranean so far this year while trying to make the desperate journey to a better life. Many came via Libya, which has now emerged as the favoured point of departure for the people-smugglers. Failed states are invariably attractive to criminal gangs, and that includes IS.

It cannot be said too often that for the overwhelming majority of Muslims -- whether in Syria, Iraq, Libya, Tunisia, Yemen, or Mali -- IS is a terrifying, alien force. The bloodthirsty zealots who commit atrocities under its banner are no more representative of Islam than Dylann Roof, the alleged racist killer of nine black worshippers in Charleston, South Carolina, two weeks ago, is representative of white people.

There is no easy or quick way to defeat IS. But Denmark has come up with one approach that seems to have had some modest success, at least in reducing the number of young Danes tempted by jihadi ideology, offering them intensive counselling and support via a network of social workers, teachers, youth club workers, and outreach workers. (It was featured in a programme on the BBC World Service this week and you can read more about it here.)

The Danish model doesn't offer a complete solution by any means -- but it does make a start, because the people who join IS are angry and alienated, whether they come from Denmark, Tunisia, or the UK. They believe in a perverted brand of Islam that is as far from the Muslim mainstream as the Christian Phalangists responsible for the Sabra and Chatila massacres in Lebanon in 1982 were from Lambeth Palace.

So will sending the RAF to bomb IS targets in Syria, which seems once again to be on the agenda, help to protect future British holidaymakers on Tunisian beaches? I doubt it very much. It might, however, help to prevent IS extending its reach in Syria -- and that would doubtless be welcomed by many thousands of Syrians.

We will probably never know exactly why Seifeddine Rezgui chose to open fire on Western tourists on that Tunisian beach a week ago -- but one thing I am sure of: dropping British bombs on IS targets in Syria wouldn't have stopped him, any more than it will stop others like him trying to emulate his murderous rampage.

After all, as The Guardian pointed out in an editorial this morning, the US, Canada, Jordan, Bahrain and Saudi Arabia are already bombing IS in Syria without significant effect.  A few more bombs courtesy of the RAF are unlikely to make much difference.