When the new British government was established, David Cameron and Nick Clegg promised to ‘make this coalition work in our national interest’. The term ‘national interest’ is used ubiquitously by politicians these days – but how should the UK define our ‘national interest’ in the modern world? An answer given by the Prime Minister to a parliamentary question lamely referred to paragraph 2.12 of last year’s National Security Strategy (NSS): ‘Our security, prosperity and freedom are interconnected and mutually supportive. They constitute our national interest.’

This cannot represent the sum total of the British government’s analysis of Britain’s national interest.  A nation’s national interest is, of course, not a static but a dynamic concept which needs to be constantly reassessed and questioned. This requires an ongoing process of strategic thinking – both within and across the whole of government – and with input from beyond the normal boundaries of policy makers. The national interest should be the criterion against which politicians judge what their policies and actions should be, rather than just a sound bite to be deployed at a convenient point in a speech.

Suddenly, it is clear why there is unease about British foreign, defence and security policy. Look how the British government has responded to the crisis of legitimacy in Arab countries. Before the election, David Cameron seemed to aspire to a different kind of foreign policy from his predecessors, with less reliance on hard power. Instead the British people were promised ‘a distinctive British foreign policy that extends our global reach and influence’. But had it really been thought through? How could the government build up ‘significantly strengthened bilateral relations for Britain’ while handing over more and more influence to the EU? How could Britain secure its freedom and prosperity in an unstable world while cutting back on the means of strategic influence and security? The Foreign Office is being squeezed and the BBC World Service cut, while the Strategic Defence and Security Review (SDSR) has reduced Britain’s deployable military capability by one-third.

Without a clear conception of the national interest, policy has no anchors. In essence, there is increasing concern in Parliament and among commentators that the leadership is intellectually incoherent. The Chancellor of the Exchequer made only one reference to ‘the national interest’ in his emergency budget statement last summer – and that was to justify an increase in spending on overseas aid. He may be correct, but nowhere has there been a comprehensive assessment to justify this claim. It has been said that aid spending in potentially failed states forestalls future conflicts and security threats. Well, where is the analysis? And where is the assessment which balances the advantage of such spending against, say, the advantage of maintaining carrier strike capability or maritime reconnaissance?

One of the reasons politicians prefer to do their own strategic thinking is that an objective assessment of spending priorities against coherently-assessed national interests would open up all kinds of questions, which politicians of all parties might prefer to avoid. Public spending priorities obviously reflect politically-driven considerations. But such decisions should not be made blind to the genuine national interest,  based on no more than a hunch that it feels or sounds right when announced.

The new government’s NSS and the SDSR have already been rendered out–of-date. There have now been perhaps six strategic shocks since the SDSR: a currency collapse, two earthquakes, a tsunami, a nuclear meltdown and five Arab insurrections among them. Events have thrown David Cameron’s preferred foreign policy back to something more like that of the Labour government under Tony Blair.

This generation is living through a period of intense global instability, arguably unmatched since the 1930s, fuelled by over-population, competition for resources, resurgent Islamism, nationalism and extremism, technology, as well as global communications and networks. British strategy seems to be based on the assumption of ‘known knowns’ – or at least ‘known unknowns’ – rather than the increasingly frightening world of ‘unknown unknowns’ we now live in. There is a growing feeling in the UK that there must be a better way to assess Britain’s national interest, and refresh its national security strategy accordingly, by introducing the proper infrastructure and capacity for sustained strategic thought.

During the Public Administration Select Committee inquiry into ‘Who does UK National Strategy?’ last year, the Foreign Secretary stated that there have been two ‘givens’ of British foreign policy for the past 50 years: the security alliance with the US and Britain’s economic and political relationship with Europe. But with the US increasingly turning towards the Pacific rather than the Atlantic – and with the EU preoccupied with its own internal crisis – is this the right way for the UK to view the world for future policy? The UK needs to ask itself fundamental questions such as where the UK’s trade and investment opportunities lie in the next 50 years. How should the UK play to its strengths?

There are difficulties with provoking such a fundamental debate about ‘our’ national interests, which presupposes that ‘we’ all know who we are. Britain is being changed and challenged by relative economic decline, a continuing loss of pre-eminence in industry, science and education, by the after-effects of devolution and a period of mass immigration. Are we still a ‘United Kingdom’? If so, how should this be articulated? Unless the government has a clear view of the collective identity it is meant to be speaking for – and acts on these views – subsequent policies will continue to appear uncertain.