London 2012 has been spectacularly successful. Aside from Team GB's stunning medal-winning exploits, the Olympic naysayers have been confounded by the infectious enthusiasm of the crowds and the thousands of volunteers, the streamlined organisation of the Games and the tremendous dignity with which most competitors have greeted victory and defeat alike. As one newspaper editorial commented, the Olympics have produced an unprecedented, shared sense of 'national good feeling', celebrated in all corners of theUnited Kingdom.

But what comes next? Lord Moynihan, chairman of the British Olympic Association, sparked what will be a growing debate in the coming weeks by declaring at one of his press conferences that we are at a crossroads in sports policy. Without a step change in approach, he argued (making claims soon echoed by other influential figures such as Sir Keith Mills, deputy chairman of LOCOG), a unique opportunity to raise participation levels in sport and deliver the Olympic sporting legacy would be lost. 'We are calling on the government to use the momentum that has created so much inspiration in this country', Lord Moynihan said, 'to create practical opportunities in schools, clubs and local communities for kids to get into sport and stay in sport'.

My view looking back as a historian, author of the recently published Sport and Politics in Modern Britain: The Road to 2012, is that we should not lose sight of how far government policy has developed since the days of the 1948 Olympics, when it was taken for granted that sport and politics did not mix. Since the 1960s assisting Olympic athletes, improving local recreational facilities and increasing participation rates have been standard objectives, pursued with varying degrees of vigour by different governments. After 1997 Tony Blair's 'New Labour' administration built on foundations laid by John Major's Conservative government, using the injection of National Lottery funding in particular to invest heavily at all levels of sporting provision. School sport was revived after a long period in the doldrums, and the success of Team GB at the Olympics from 2000 onwards stemmed in part from high levels of funding as part of a coherent approach to elite sport.

State involvement in sport is much greater than a generation ago, although at the same time sport policy has always been overshadowed by some enduring problems. The levels of direct Treasury investment in sport, for example, compared with Lottery funding, remain tiny in comparison with the budgets provided for other areas of social provision. The millions devoted annually to encouraging higher levels of participation via bodies such as Sport England are, in the words of Guardian journalist David Conn, 'heartbreakingly small' compared to the £9.3 billion budget provided for a few weeks of Olympic competition.

Recurrent funding problems reflect the fragmentation of the sport policy-making community. Sports Ministers have to deal with a myriad of delivery agencies, and the post of Minister for Sport has always been a lowly one in the government hierarchy. Although the Department for Culture, Media and Sport has had oversight of policy since 1997, other Whitehall departments retain responsibility in specific areas – the Department for Education's role in school sport being a case in point – making a unified strategy more difficult to achieve: as was made obvious when Michael Gove as Education Secretary decided in 2010 to remove much of the funding for School Sports Partnerships.

Another perennial difficulty for sport policy has been shallow levels of political support – among MPs atWestminster, acrossWhitehall, and around the Cabinet table - and a high degree of dependence on the personal interest of particular prime ministers. Harold Wilson in the 1960s and John Major in the 1990s were great enthusiasts for sport, and since the turn of the century all incumbents of Number Ten have vigorously backedLondon's Olympic ambitions. But other prime ministers such as Margaret Thatcher were indifferent or even hostile, and for the most part over the past half century sport has occupied a lowly place in the political pecking order.

Despite strong backing for the Olympics, since 2010 – in the wake of a massive programme of spending cuts – the sense of an integrated government sport policy has been lost. Labour's record under Blair and Gordon Brown was open to criticism, but there was a least a conscious attempt to link together school, community and elite sport and to deploy sport in the interests of wider community goals. As well as the emasculation of the widely-praised School Sports Partnerships, the Coalition has scaled back on targets for getting increased numbers of adults doing more sport and physical activity – this despite the recent study published in The Lancet suggesting that inactivity was now a greater cause of premature death than smoking.

On the basis of past practice, securing a genuine sports legacy from London 2012 hangs in the balance. What then should be done? Aside from a growing consensus about the need to revive (or more accurately re-revive) school sport, one urgent requirement – as I argued in a recent paper found at www.historyandpolicy.org/papers/policy-paper-133.html - is for the formulation of a new national strategy. Sport policy requires a radical, authoritative and comprehensive statement by the government that goes back to first principles to weigh up the value of sport to society; outlines realistic, deliverable targets in return for investment; sets out how sport should be deployed in the interests of wider goals such as combating crime and obesity; looks afresh at how to inspire children through school sport; and determines what administrative framework - incorporating delivery agencies, governing bodies and local authorities as well as Whitehall departments - can stitch together the bonds of school, community and elite sport.

For the moment Coalition leaders appear guilty of continuing the past practice in sport policy of reacting on the hoof, suddenly pronouncing for example on the need to increase competition in primary schools. But the appointment of Lord Coe as a high-profile ambassador, commanding equal respect in the sporting and political worlds, offers some hope that the sporting legacy of 2012 will receive serious consideration. The danger that sport will be relegated to the margins of government policy, as so often in the past, has at least been minimised.

Kevin Jefferys (author of this article) is Professor of Contemporary History at Plymouth University