There is a case for bombing Syria. But it's not as simple as David Cameron says

As soon as news broke of the Tunisian hotel massacre in June, many ministers automatically assumed that Britain had been hit by the so-called Islamic State of Iraq and the Levant (Isil) in an attack planned from its headquarters in Raqqa. If so, the case for the RAF bombing that city would become overwhelming: Britons had been killed, so we would respond. The lead attacker had planned the murders on his laptop, which he had flung into the sea. It was recovered, his attack notes discovered and the identity of accomplices established.

But there was no link to Syria; the atrocity had been planned entirely from Libya. So military action would have to wait.

When your enemy doesn’t have a fixed location, he’s harder to hit – as the Americans have found out. For almost 18 months, they have been bombing Isil’s suspected positions in Raqqa, and have so far killed an estimated 20,000 people. Each day, the city reverberates to the sound of allied attacks: the US has been joined by Jordan, Saudi Arabia, Australia, Turkey and Bahrain who have together dropped more than 2,800 bombs on Syria.

During the time these operations have been under way, Isil has gone global with attacks not just in Tunisia but in Beirut, Ankara, Yemen and, most recently, Paris. It’s the paradox of terrorism: militarily, the jihadists are no match for the West, but all of this bombing has, so far, resulted in stalemate.

David Cameron didn’t talk much about this yesterday. Indeed, listening to him address MPs, it all sounded rather simple – as if the enemy was lying unmolested, thumbing its nose at West and daring the RAF to and visit. “Every day we fail to act,” he said, “is a day where Isil can grow stronger.” But every day, the US spends about £7 million on an Isil campaign which has had depressingly little effect. If the RAF joins, Western forces may make 55 air strikes a week rather than 50. If Britain becomes the 13th member of the Syria coalition it will be welcome. But militarily, the effect will be marginal.

There is a great temptation for a politician, when making the case for war, to simplify or exaggerate. And, in so doing, ruin their case. For example, the Prime Minister revealed to MPs that there was an army of 70,000 moderate Syrian rebels ready to move against Isil. He then suggested a straightforward plan: that Raqqa is bombed, the Islamic State routed by Western-armed rebels and then a political settlement is reached with a new government in Damascus which unites Syrians.

It’s a wonderful ambition, but one that seems even more optimistic than his plan for stable government in Libya. Those 70,000 rebels, for example, don’t exist as a coherent force; half of them are in the north, half in the south, and all fighting a multidimensional civil war. The Americans have recently had to abandon their plan to raise a rebel army, after finding that many are far more interested in fighting the Assad regime (or each other). Arming Syrian rebels is a very dangerous business, because you never know who they’ll fight. “This is one of the sad realities,” says Ash Carter, the US Defence Secretary. “They’re harder to find than you would like.”

Bombing alone won’t work because Isil has been digging in, banning Syrians from leaving Raqqa and in effect using its 200,000 citizens as human shields. The jihadists abandoned their military compounds long ago and are based in the residential neighbourhoods which, they know, makes them bombproof: every drone strike needs to be calculated to have minimal civilian casualties. The bombing is proceeding at a relatively slow pace not because the Americans lack reinforcements. It’s because it’s hard to find targets whose destruction won’t kill ordinary Syrians

Nor is Barack Obama in a rush to move. François Hollande’s take – that France will embark on a “pitiless” war – finds no echo in the White House. After Paris, Obama’s message was caution – to overreact, he said, would play into Isil’s hands. “They’re a bunch of killers with good social media,” he said recently. To treat them as an existential threat would “buy into their fantasy that they’re doing something important.”

Mr Cameron disagrees; he sees this as a “generational battle”. But Britain is in no position to do things on its own. After five years of running down the Armed Forces, we have relatively few aircraft to spare. Our campaign against the Islamists in Iraq has been stepped up recently; we now supply 8 per cent of the bombs dropped, rather than 5 per cent. But still not much to make a difference militarily. The best that Britain can do is make the case for speeding things up in Syria – but to do this, we need to be a full ally. At present the Prime Minister finds himself at the sidelines, to his immense frustration.

And this is the case for acting in Syria. This is a political mission more than a military one. For years, Britain has been haemorrhaging influence in Washington – diplomats there have been shocked to hear France being mentioned as America’s most reliable European partner. Our absence from the Syria campaign stands out – and sends worrying signals about our reliability as a partner. With our troop numbers being cut back, we need partnerships. And this means stepping up to join alliances when the time comes.

This is harder for the Prime Minister to explain. It’s fairly easy to talk in terms of Britain bombing Isil into submission before sending in a 70,000-strong army. It’s harder to admit that bombing hasn’t really worked, and that that army doesn’t really exist and that a better strategy is needed. But if we want a chance of influencing that strategy, we need to join the US-led coalition.

The best case for intervention in Syria yesterday was made not by any minister but by Bob Stewart, a former colonel and now a Tory MP. He had been talking to senior officers in France, he said, and they told him that the country feels attacked and would very much appreciate the support of its closest ally. So it’s time, he said, for a “highly potent gesture” to let our allies see that we’re fully behind them. It’s a less dramatic case for war, but it’s more credible. And far more likely to give the Prime Minister the parliamentary vote that he so badly needs.