LONDON (Reuters) — The use of high-level diplomacy to end the stand-off over 15 British sailors held by Iran offers hope progress could eventually be made towards a compromise over Tehran’s nuclear ambitions.Analysts said the involvement of the top foreign policy adviser to British Prime Minister Tony Blair in talks with Iran’s chief nuclear negotiator Ali Larijani, opening a new communication channel with Iran, was significant. “There may be more of a disposition to try to find a way to get into negotiations on the nuclear issue, now that Iran has demonstrated that negotiations on this issue of detained service people can be productive,” said Mark Fitzpatrick, senior fellow for Non-Proliferation at the Institute for Strategic Studies.

The seizure of the 15 sailors and marines in the northern Gulf came at a time of heightened tensions over UN efforts to persuade Iran to halt its nuclear programme, which the West fears is ultimately designed to produce atomic bombs.

Senior British government sources also say many Arab nations were worried about Iran’s behaviour, especially the parading of the captives on television, and pressured Tehran to back down.

They say increased concerns within the region may help bring influence to bear on Iran in other areas including its nuclear nuclear ambitions.

“More thinking people within the (Iranian) system will recognise that they’ve made a blunder and conclude that they’ve lost further ground in terms of international opinion,” said a senior British government source. “In terms of the long-term goal — which is to influence the politics inside Iran in a way that determines that a resolution of the nuclear file through negotiation is in Iran’s best interests — I think that’s probably helpful.”

The sudden release of the 15 British sailors and marines by Iranian President Mahmoud Ahmadinejad came the day after Blair’s adviser Nigel Sheinwald spoke to Larijani, reaffirming that Britain wanted a diplomatic solution.

The European Union’s foreign policy chief, Javier Solana, also discussed prospects for talks on Iran’s nuclear programme and the sailors with Larijani the day before their release. Few analysts or diplomats expect an early breakthrough on the nuclear dossier. But they say the isolation of Iran within the region over the crisis, and the influential role played by Larijani in getting them released, may help.

“Larijani is certainly building up his power in Iran, so a new direct channel of communication between Downing Street and Larijani might lead to some traction on the nuclear issue, although that’s a much more complex case,” said Alex Bigham, Iran specialist at the Foreign Policy Centre in London. Larijani is regarded as a pragmatist more amenable to exploring a bargain with the West than hardliner Ahmadinejad. Last year Sheinwald established relations with Syria’s President Bashar al-Assad, who is keen to bolster his image as an influential player in the Middle East. Sheinwald will also become Britain’s ambassador to Washington later this year.

“He’s been a critical player in British foreign policy and he’ll continue to be so. He’s engaged in relations with the Syrians and tentatively with the Iranians so that may be useful in Washington,” said Bigham. Senior British government sources say the role of Syria, one of the many countries in the region lobbied by London to resolve the crisis, was significant.

“It’s the closest regime to the Iranians in a whole lot of areas, and to have them saying to Tehran, in whatever language they used, ‘This isn’t sensible’ must have had some influence,” said one government source.

Iraq, Afghanistan, Turkey and Saudi Arabia were also all active in putting pressure on Tehran, they say. Blair said on Thursday that Britain should exploit its “new and interesting” access to influential leaders in Iran, but remain “absolutely steadfast” about getting Tehran to stop developing nuclear weapons or supporting terrorists.

While some analysts say the prospect of a “rosy scenario” — a more benign policy towards Iran from Washington, and the engagement of Syria — may have increased, the possibility of a US attack on Iran has not been banished.

“It’s very encouraging that there are these high-level contacts, and one would hope they can work towards some compromise,” said Dan Plesch, author and commentator on nuclear proliferation at London’s School of Oriental and African Studies.

“But I think the international political class underestimates Washington’s immediate ability to deliver ‘shock and awe’ ... So the dismal scenario is that this will form part of an emerging crisis over the summer.”