Will the world ever step in to stop the Syrian slaughter?

As the West's rhetoric has escalated, so has the death toll from Assad's killers. Kim Sengupta asks whether a military response is anywhere on the horizon

Syria is not Libya – that was the oft-repeated mantra of senior military officers as they gathered last week in Whitehall for talks. They had come together to discuss the future of land warfare and how the British Army would cope with its numbers being slashed by a fifth. After the long wars in Iraq and Afghanistan, the prevalent feeling was that this was a time for retrenchment and reflection, rather than sending expeditionary forces into battle in far-off lands.

The senior officers at Rusi (the Royal United Services Institute) debated what can be achieved in Afghanistan in the two-and-a-half years left before international forces withdraw, the lessons learned from the Libya missions and the threats of the future, such as cyber warfare.

No one thought that British forces should get sucked into the Syrian civil war and the Americans present could not foresee their involvement either. Thus it was something of a surprise for the commanders to hear the Foreign Secretary William Hague declare on television two days later – as 4,100 more service personnel were about to receive their redundancy notices – that he could not rule out British troops being sent to Syria.

"It is looking more like Bosnia in the 1990s, being on the edge of a sectarian conflict in which neighbouring villages are killing each other," Mr Hague said.

More than 12,000 British troops ended up serving in Bosnia. With a UK force of 9,500 still engaged in combat in Helmand and the overall size of the forces shrinking after the Strategic Defence and Security Review, this sort of commitment simply would not be possible now.

But the arithmetic is not the only reason why senior military officers are opposed to getting involved in the battle between Bashar al-Assad's regime and the armed opposition.

A serving British General with combat experience in Iraq and Afghanistan said: "Leaving aside the matter that there was a [UN] Security Council resolution on Libya and there isn't one on Syria, we have to ask ourselves would there be the political will to carry this through if we do go in? We have seen in Afghanistan the political will wilting while ours remained strong. We have still got unfinished business in Afghanistan, We are not sure how Libya will ultimately play out. Is this really the time to start another operation? Our view is no, it's not."

For Admiral Sir Alan West, a former head of the Royal Navy, sending in British troops "would be the worst scenario possible. It is indeed a civil war in Syria and increasingly a sectarian one and the last thing you want to do is to introduce Western troops on to the ground in such a volatile situation. All you'll be doing would be further inflaming regional tensions.

"Of course, everything that can be done must be done to stop the killings, but this is not the answer. In any event the Europeans would not be able to do it by themselves, the Americans will have to be involved, but I wouldn't have thought the Americans would want to put their hands into the mangle in this one."

General Sir Mike Jackson, who led Nato forces into Kosovo and was the head of the Army during the Iraq war, said: "We can certainly hear the noises for intervention rising and these things have a political momentum of their own; with each atrocity there would be more pressure.

"But we must exercise caution. Syria is not Libya, any intervention there carries huge risks. The UK cannot, of course, carry out anything like that alone; it'll have to be done multinationally and I can't see the enthusiasm to do this. It may be possible to set up a humanitarian corridor and this could well be worthwhile. But that is very different from a Balkans-type intervention."

Brigadier Ben Barry, who has extensive experience of serving in Bosnia and is now the senior fellow for land warfare at the International Institute for Strategic Studies, said: "There are similarities with what is happening in Syria, but also significant differences. In the Balkans all three sides formed armies fairly quickly from the old Yugoslav army and formed their own enclaves, so borders of sorts could be established; that is certainly not the case here. We also need to bear in mind that there is a possibility the Israelis may carry out their threat of carrying out strikes on Iran. This is probably not the time to internationalise another conflict in the region."

Despite facing virtually no anti-aircraft defences, it took seven months of Nato bombing to facilitate victory for the Libyan rebels over Muammar Gaddafi's regime. Syria has an estimated 90 fighters and 240 ground attack aircraft, most of them Russian-made MiG 23s and MiG 21s, Mi-24 Hind helicopter-gunships and 4,700 surface-to-air missiles in an air-defence system augmented recently, it is believed, by the Russians and the the Chinese. The army is 300,000-strong with an equal number of reservists and, unlike Libya, there have not been many defections, especially from senior ranks.

Admiral West said: "We know the type of air defences they have, double-digit SAMs [surface to air missiles] and the like and if we send in the Tornados, for example, we can expect to lose a few, that is unless the Americans put in a fair amount of suppression with things like their Growlers (electronic warfare aircraft). "These are the types of risks one faces in conflicts, but the important thing is that the public should know about these risks."

Armed intervention: the case against

Limited international support

Unlike Libya, there is no UN resolution authorising military action.

Provocative act

Putting Western troops on the ground in such a volatile region would be an incendiary move.

Lack of political will

The UK is in no position to carry out such a mission by itself and neither is Nato without US help. Barack Obama has shown no desire to get involved militarily.

Strength of Syrian forces

It took Nato months of bombing against virtually no air defence to help Libya's rebels to victory. The Syrian defences are far stronger.

Regional volatility

With the possibility of Israel launching strikes against Iranian nuclear plants it is not the time to internationalise a second conflict in the region.

UK defence cuts

With the savage cuts of the SDSR and the long wars in Iraq and Afghanistan it is time for Britain's armed forces to retrench rather than embark on another mission.