An agreement banning cluster bombs has cheered human rights campaigners, but powerful military states are refusing to join it and experts say the treaty is riddled with holes and could prove unworkable.
The agreement, to be formalised in Dublin today, commits 111 countries to banning the use of cluster munitions - "bomblets", usually scattered from the air, that detonate like mines.
But the United States, China and Russia have side-stepped the deal, and while Britain and other Nato states champion the ban, the treaty has loopholes that would allow British troops to benefit if an ally like Washington uses the weapons.
"This is an absolutely rock-solid treaty that's going to outlaw a lethal munition," said Mark Garlasco, an analyst at Human Rights Watch, pleased with what he saw as the fruitful outcome of 10 days of talks in Dublin.
"This is going to outlaw 99.9 per cent of the cluster munitions out there ... which will stigmatise the weapon even for those countries that aren't signatories to the ban."
Despite that confidence, however, Mr Garlasco and other campaigners acknowledge that the treaty, due to be signed in Oslo in December, has clauses that soften its impact, leaving it with significant moral weight but arguably less substance.
"There are a number of countries that are important military powers that have not signed this treaty," conceded Thomas Nash of umbrella group Cluster Munition Coalition.
But he added: "What you will see is a very profound stigmatisation of this weapon ... Countries like the United States are not going to be able to use cluster munitions in the future without facing a huge public backlash."
The United States, the world's largest military power, has made clear it intends to go on using the bombs when it sees fit.
"While the United States shares the humanitarian concerns of those in Dublin, cluster munitions have demonstrated military utility," State Department spokesman Tom Casey said yesterday, adding that to join the ban would put US soldiers' lives at risk.
Israel, which made widespread use of cluster bombs during its 2006 war with Hezbollah in southern Lebanon, has reiterated its intention to go on using them, and India and Pakistan are also notable non-signatories of the treaty.
Article 21 of the agreement would let British troops call in US air support that might include planes dropping cluster bombs, although British forces would not themselves use them.
"The whole thing is like a Gruyere cheese - it's completely full of holes," said Nigel Inkster, an analyst at the International Institute for Strategic Studies in London.
"If you think that a person with a very real threat in front of them, a threat that would be alleviated by the use of cluster bomb munitions, isn't going to use them ... it's a no-brainer.
"It just seems empty in so many ways," he said of the deal.
British Prime Minister Gordon Brown pushed hard for a ban, even though the British military often employs cluster bombs.
A British foreign office spokesman attending the talks played down suggestions Brown had overridden military objections to sign up to the treaty, and said Britain now hoped to use its position to persuade others to agree to the ban.
"We hope that by the position we've adopted others may eventually follow suit," he said.
"The US-British alliance and the ability to work with our allies is critical, and article 21 is very helpful on that."