Nato is back, or is it?

Nato says it has reinvented itself to confront new security threats after a deep "relevance crisis" following the September 11 attacks on the United States, but the jury is still out on the role of a revamped alliance.

At a two-day summit in Prague, leaders of the 53-year-old Western defence organisation agreed to take in new members, create a new strike force, acquire new equipment and build new partnerships stretching into Central Asia and the Caucasus.

Above all, by calling Nato "our nation's most important relationship", President George W. Bush renewed the US commitment to an alliance that influential forces in his administration had appeared to regard as at best a toothless cheerleader, and at worst a dinosaur.

"Nato is back, or at least this summit gives us a very good chance of a comeback," a senior Nato official said.

But success may depend on whether Washington chooses to use Nato in any war against Iraq, and whether European allies deliver on pledges to modernise their defence forces.

On both fronts, the outlook is uncertain. Morale in Nato hit a low when the United States sidelined the alliance from its military campaign in Afghanistan last year after the allies invoked their mutual defence clause for the first time and offered unlimited support.

Disenchanted by the experience of waging "war by committee" in Nato's air campaign over Kosovo in 1999, the Pentagon bluntly told the Europeans: "The mission defines the coalition."

Many allies were dismayed at effectively being told: "Don't call us, we'll call you." The US-led "war on terrorism" was accompanied by a barrage of commentary belittling the Europeans as wimps and declaring Nato irrelevant to international security.

Struggling to revamp a battered, bureaucratic organisation, Nato Secretary-General George Robertson warned European allies they would be "military pygmies" unless they spent more on defence and acquired new war-fighting capabilities.

So what, if anything, has changed after Prague? Spurred by Robertson and anxious to avoid being treated as negligible by Washington, the allies signed up to their most specific commitments to acquire new military capabilities for long-range warfare.

These include airlift, sealift, precision-guided munitions, air-to-ground surveillance radars and aerial refuelling tankers.

Nato officials say they are confident, even though those pledges were not made public, that they are sufficient to create peer pressure to achieve results by enabling Nato to name and shame those who do not deliver.

They also seized on a US proposal for a 20,000-strong Nato Response Force for rapid deployment in a crisis as a chance to combine their existing strike forces more purposefully.

But what exactly such a force, which would require unanimity in Nato's soon-to-be 26-nation council to go into action, would do remains to be determined.

Military analysts say a unit that size could only be the spearhead of a larger military operation or fulfil small-scale tasks such as hostage rescue or "extraction" which some see as beneath Nato's ambitions.

Nevertheless, the new commitments, and the infectious enthusiasm of Nato's aspiring new members and partners, helped change the tone of US policymakers at the summit.

Defence Secretary Donald Rumsfeld, often seen as the leader of the Nato-sceptical camp in Washington, told reporters he was heartened by the summit's result and by the "energy, enthusiasm and value" that the new invitees would bring to Nato.

"It looks as if Bush has sided with the Nato reform camp over the Nato-sceptics who think it's just keeping a myth alive," the senior Nato official said. "That gives us a new lease of life to get our act together."

The fact that 16 Nato countries have since got involved in Afghanistan - some sending special forces to track Taliban and al Qaeda, others leading the peacekeeping operation in Kabul - may have helped focus the United States on Nato's wider value.

Modern wars are short but their aftermaths can be long. Nato is still involved in peacekeeping years after the short air campaigns in Bosnia and Kosovo, and its military planning staff are about to get involved in the Afghanistan peace force.

Some diplomats see this as a precursor to a possible Nato role in a post-war Iraq, after a military operation likely to be dominated by US, British and possibly French forces.

Nato's wider network of partnerships in Central Asia showed its value when the United States needed bases for its Afghan operation, and practical military cooperation with countries in that "arc of instability" offers more future security benefits.

Nato officials also observe that no credible alternative to the alliance has emerged - least of all the European Union's common defence policy, which is struggling to find its feet.

"Less Nato wouldn't make more Europe, whatever the French think. Less Nato would just mean an even greater temptation for the Americans to go it alone," a European Nato diplomat said.