AS PREPARATIONS begin for NATO's Chicago summit in May, the 63-year-old alliance is facing a perfect storm of problems. Even if it can overcome them, the organisation that has formed the bedrock of European security since the ending of the second world war, and which only a few years ago aspired to become “global NATO”, faces a future of reduced means and more modest ambitions.

The gloom might seem surprising. Last year's Libya mission was a success. With Britain and France leading from the front and America from behind, NATO waged a sophisticated air war that achieved everything it set out to do within seven months, causing remarkably little damage to vital infrastructure or harm to civilian life. Even in Afghanistan, NATO members have largely kept to the commitments they made at the latest summit in Lisbon two years ago and are set to stay the course until the agreed on, if inglorious, exit of combat forces at the end of 2014.

Quietly and without much fuss (except from the ever-grumpy Russians) the first phase of the new ballistic-missile defence system to protect Europe from an attack by a rogue state (ie, Iran) is being deployed. Spain has provided a base for Aegis missile-defence ships, Turkey is the site for a new X-band radar and SM-3 interceptors will find homes in Poland and Romania.

But the big picture is a lot more troubling. Europe's economic crisis has put further pressure on already shrunken national-defence budgets. In its annual report “The Military Balance”, the London-based International Institute of Strategic Studies (IISS) noted that for the first time in modern history, Asian defence spending is about to overtake that of Europe.

Compounding that problem is America's strategic pivot towards the Western Pacific, in response to China's rapid military expansion. Published in January, the new “strategic guidance” only confirmed trends that have been gathering pace for many years. America's statement that Europe should now be a producer of security, rather than a consumer, combined with an announcement that a quarter of the remaining American forces stationed in Germany would soon be coming home, carried an implicit warning to the European members of NATO.

Turning on Tripoli

In retrospect, the Libyan war may have been in several ways a turning point for the alliance. It was the first NATO campaign in which Britain and France, rather than America, were in the driving seat. Some members of the Obama team were convinced of the need for humanitarian intervention and a demonstration of support for the Arab spring. But others, notably the then-defence secretary, Robert Gates, saw no vital American strategic interest at stake and were determined to provide only just enough help to ensure that the slender arsenals of the European allies did not doom the mission.

In his valedictory speech—given in mid-campaign—Mr Gates lambasted his European allies for the slow progress against a puny opponent and for failing to invest in the capabilities that America was forced to provide, such as air-defence suppression, ISTAR (Intelligence, Surveillance, Target Acquisition and Reconnaissance) and aerial refuelling. Unless the Europeans plugged those gaps, he questioned, how much longer would America see NATO as a militarily useful partner?

Some of Mr Gates's criticisms were unfair. Those gaps exist in part because America has urged its allies to avoid useless duplication. But his main point was that Europe had grown used to a free ride on American defence spending (which, as a share of GDP, is about three times the European NATO average). Instead it should at least be able to take care of security in its own backyard. This does not challenge—at least directly—NATO's main promise, of American help against an attack on a European member country. But in future, America may be reluctant to lead even from behind in helping the Europeans deal with emerging threats or humanitarian calamities in their own near abroad.

In response NATO's energetic secretary-general, Anders Fogh Rasmussen, is touting something he calls “smart defence”—a new label for the 20-year-old idea of pooling and sharing resources, setting better priorities and encouraging countries to specialise in the things they are best at. Mr Rasmussen hopes members will agree to more than 20 projects before the Chicago summit, each led by one member country. These include the pooling of maritime patrol aircraft; the acquisition of five Global Hawk long-range reconnaissance drones; and a support package for deployed helicopters. Other schemes covering logistics, training and force protection are expected to follow.

Despite universal lip service to smart defence, scepticism abounds. François Heisbourg, chairman of the IISS and of the Geneva Centre for Security Policy, says that governments all too often choose jobs in defence companies at home over military logic.

Libya also showed how national vetoes over the use of military assets can disrupt missions. When it comes to “wars of choice” European countries with different histories and geographies may disagree. Only eight out of 28 allies conducted strike sorties over Libya. Germany, which abstained on the UN resolution authorising the mission, went so far as to withdraw its crews from NATO warning and control aircraft and its warships from other NATO missions in the Mediterranean. In a future conflict, if, for example, one or two countries that had made a large contribution to a pooled fleet of air-to-air tankers decided to sit out the campaign, what would happen to the assets they had paid for and helped to operate?

Mr Rasmussen is looking at “assurance of availability” contracts signed between participants in a pooling arrangement. But even if this would raise the political bar for refusing to take part, no contract can remove the risk altogether. Furthermore, the voters of the biggest and richest country in European NATO—Germany—are resistant to the use of force in almost any context. That hangs uncomfortably over the whole smart-defence idea.

The endgame in Afghanistan casts a gloomy shadow, too. After the optimistic early years, many are now impatiently counting the days to December 2014 when NATO is due to cease combat operations and the transition to Afghans' responsibility for their own will in theory be complete. A NATO training mission will endure beyond 2014, but its longevity will depend on how Afghan forces perform. The picture will be messy, confused and probably disappointing.

But, for all its woes, the mission gave the alliance cohesion and a purpose that it may now lack. Some European governments feel that their support for a war with little popular backing may have been taken too much for granted by America. But on the ground, respect has grown. American generals have been surprised and gratified by their allies' grit in a largely thankless task. They have also noted how even allied forces of initially limited effectiveness improved dramatically after working alongside their American partners. That shared experience will rapidly become just a memory. As American combat brigades leave Europe, joint training will suffer. That will hurt one of NATO's central objectives: interoperability between American and European forces.

The summit will reaffirm the strength of the transatlantic partnership and Mr Rasmussen will insist that smart defence can confound the cynics and pave the way for “doing more with less”. But what the future is more likely to hold is benign neglect by America and declining military ambition in Europe. In other words, unless something changes, NATO will end up just doing less with less.