Dr Paul Cornish
(Former Chatham House Expert)

The murders in Northern Ireland of two British soldiers and one British police officer make it clear enough that there are still those whose preference is violence and brutality, rather than stability and democracy. If there is some comfort and reassurance to be gleaned from these brutal events, it is that the people of Northern Ireland appear more determined than ever to prevent a re-emergence of the troubles. Stability and normality have been tasted, and they are far better than the alternatives which have for too long been on offer in Northern Ireland.

But what happens now, and what conclusions should be drawn about the organisation of UK national security? Some might argue that the armed forces, as well as the security and intelligence services have all been allowed to take their eye off the Northern Ireland ball too soon, and have prematurely redeployed scarce resources to fight military campaigns in Afghanistan and Iraq and to meet new counter-terrorism challenges in the UK and internationally. And if the armed forces and intelligence services are already fully committed to these tasks, how will they cope with a renewed effort against terrorist groups in Northern Ireland? Have we finally reached the point where overstretch - in both the military and the intelligence services - has compromised national security?

Britain's armed forces are certainly overstretched and under-resourced. Operational commitments in Afghanistan and Iraq have placed considerable strain on personnel and equipment, raising the possibility that British troops might at some point be defeated in battle. Some commentators claim this has already happened - in Musa Qala in 2006 and Basra in 2007. The draw-down of troops in Iraq will provide a welcome relief, but the considerable (and expanding) commitment to Afghanistan remains.

The Royal Navy, the Army and the Royal Air Force all face the prospect of the tempo of operational deployments remaining far above the level for which the armed forces have been configured, with penalties for training cycles, equipment readiness and, not least, family life. But there is nothing new in this. Armed forces have always been under strain and have always wanted better equipment and more troops; not many successful admirals or generals have ever argued the opposite case. A redeployment to Northern Ireland would certainly exacerbate the problems faced by the armed forces. Yet, even though the Army does not have a few spare infantry battalions with nothing much to do at present, the armed forces could reliably be expected to find what is needed if called upon to rebuild a presence in Northern Ireland.

It is this expectation, rather than Northern Ireland itself, which is the biggest challenge to the armed forces. With their problem-solving culture the armed forces can always be relied upon to respond to a crisis, and as a result the government can too easily get away with fudging awkward and expensive decisions about resources and equipment. In an article published in the current edition of Chatham House's International Affairs (Blair's Wars and Brown's Budgets: From Strategic Defence Review to Strategic Decay in Less Than a Decade), Andrew Dorman and I have argued that at the strategic level, UK defence has reached a state of organisational, bureaucratic and intellectual decay. Someone needs to wake up and put together a convincing - and convincingly budgeted - plan for UK national defence.

Fortunately, it is unlikely that there will be a demand for infantry battalions to be redeployed to Northern Ireland and that Britain's already overstretched armed forces will be asked to stretch just a little further, at least not for the moment. Instead, the task is more likely to be one of rebuilding the necessary police, intelligence and investigative resources, and to do so very rapidly. If so, then has the problem of overstretch simply been switched from the armed forces to the security and intelligence services which are already heavily committed to investigating and interdicting the operations of al Qaeda and its affiliated organisations around the world?

It is always difficult, for obvious reasons, not only to know what the intelligence services are doing, but also whether they have the resources they need. Generals might complain publicly about overstretch, but when intelligence chiefs need more resources they presumably make their demands without fanfare. Yet for two reasons, it is unlikely that recent events in Northern Ireland will pose a sudden and intolerable burden on the UK's security and intelligence agencies. These are organisations which know how to operate on a small scale and deliver high-level effect. In other words, managing complex information and intelligence networks with relatively few people is what these organisations are good at, and so they should be able to take any new or renewed tasks in their stride, without the need for urgent additional resources. Second, it is unlikely that the relevant organisations will have closed the book completely on Northern Ireland and they should not therefore have to begin again from scratch.

Instead, the intelligence services face a more structural challenge and from a very different quarter. Allegations against UK intelligence agencies of complicity in torture or mistreatment of detainees are a serious assault on the reputation and credibility of the agencies. Torture is vile and unacceptable, and any such allegations must of course be investigated and dealt with in the proper way, and lessons must be learned. But a sense of proportion is needed. Perhaps because they tend not to answer back publicly, the agencies are vulnerable to the casual, yet increasingly fashionable assumption that intelligence officers are little more than unsupervised, ruthless mavericks making up the rules as they go along. They tend, instead, to be people of good will who work within the law in pursuit of national security, and often at some personal risk. Sometimes this work will be unpalatable, and sometimes the provenance of important information - which might save lives - cannot be assured. In the light of current controversies, we might wish to supervise, regulate and sanitise every aspect of what the intelligence services do. But in the real world of counter-terrorism this might not always be possible or wise, and in the light of current security threats we should perhaps be wary of what we wish for.

Restoring the stability and security of Northern Ireland is a serious and urgent problem. But it is not a problem which is about to overwhelm Britain's armed forces or its intelligence services, or bring about a sudden withdrawal from current commitments. Instead, the organisations face different challenges. The armed forces need leadership from the top; they face a crisis in political direction, operational overstretch and resourcing. The intelligence services, however, need confidence from within; recognition from the media, the political leadership and society as a whole that intelligence operations are necessary, legitimate and legal.