This week’s report on Britain’s security from the Institute for Public Policy Research deserves to land with the impact of a bomb among the decision-makers of both major political parties. Neither party currently offers a credible vision for the nation’s defences, or acknowledges the brutality of the economic choices. Both Labour and the Tories merely promise a post-election defence review. This could scarcely be completed before 2011, delaying implementation for much longer.

This Westminster policy vacuum is exposed by the IPPR’s Shared Responsibilities: A National Security Strategy for the UK . It has been drafted by a commission of mandarins headed by Lords Ashdown, Robertson and Guthrie and Sir David Omand. Their views can scarcely be dismissed as those of mavericks. They propose a recasting of national strategy to address as an integrated whole problems of weapons procurement, counter-terrorism, energy security and alliance relationships. Today, responsibility is dispersed among government departments, some of whom seem barely to communicate.

The report cites the notable example of aid. The creation of the new Department for International Development has emasculated the Foreign and Commonwealth Office, which no longer controls the disbursement of overseas funding. DfID has become notorious for conducting its affairs apparently oblivious of foreign policy or defence interests.

The commission’s recommendations extend from urging the importance of increased natural gas storage capacity to demanding more high-security police cells. It urges promoting greater awareness of security threats beyond Whitehall to local institutions, companies and citizens. It argues for a stabilisation and reconstruction force to support military deployments such as those in Iraq and Afghanistan.

Media attention is bound to focus upon the report’s criticism of current defence policy, or rather lack of it. The government remains in denial about the need to make draconian decisions about axing major programmes. The report contends that the foremost priority should be to increase army numbers, probably by about 15,000 men, with matching support capability including more helicopters and transport aircraft.

The only credible means of funding this would be to drop the navy’s two planned aircraft carriers and the F-35 Joint Strike Fighter designed to fly off them. This would save more than £20bn, at a time when it has just been revealed that the carriers’ costs have risen by £1bn before they leave the drawing board. The commission also proposes a review of the planned Trident nuclear deterrent upgrade. It perceives a case for sustaining a minimal British nuclear capability, but is doubtful that the country can afford at least £20bn to keep Trident. This is a view increasingly widely shared among strategic analysts, but still strongly resisted by both Tories and Labour. They fear political fallout from renouncing the nation’s “big willy” missile system.

The report urges more European co-operation on strategic and procurement issues, to diminish dependence on the US. There is little doubt of the desirability of such a policy, but there must be deep scepticism about its viability. To an extraordinary degree, and despite France’s re-entry into Nato’s military organisations, the major European nations renounce credible defence policies. Unless there is a dramatic sea change of continental opinion, it is hard to see a basis for strengthening the real military links, as distinct from paper structures, between Britain and Europe.

The IPPR argues that future national security policy should be made on the assumption that “disorderly states” and non-state actors pose a greater threat to Britain than inter-state war. It also suggests the commitment in Afghanistan is in danger of failure, unless future combat operations are conducted alongside a more effective reconstruction effort.

It would be naive to suppose that much, if any, of the IPPR’s visionary shopping list will be adopted by the government before an election. The best hope is that it might stir the Tories from their long slumber, and persuade David Cameron to commit some cleverer people to developing his party’s policy. The IPPR report is an outstanding document. It highlights the scale of the government’s neglect of security for years past, and the gravity of choices that should properly have been made yesterday.

The writer is an FT contributing editor