Hopes that Iranian President Mahmoud Ahmadinejad's letter to US President George W. Bush offered a way forward in the standoff over Iran's nuclear programme have, sadly, quickly faded. The letter's wide-ranging discourse on international relations contained no specific proposals. It was a tactical move timed to coincide with tough negotiations in the United Nations Security Council on a US-backed resolution that would legally require Iran to halt uranium enrichment or face possible sanctions and military action. Nonetheless, it remains the first direct communication with the White House by an Iranian leader since the 1979 Islamic revolution and the hostage crisis at the US embassy in Tehran. That in itself is some kind of breakthrough. It should, therefore, give heart to those calling for resolution of the growing crisis by negotiation and cautioning against the use of threats against Tehran. The principal voices so far have been Beijing and Moscow, which both have important trading links with oil-rich Iran. German Chancellor Angela Merkel, fresh from an official visit to Washington, has added Berlin's view that while it supports broadly backed UN action to see that Iran does not get nuclear weapons capability, threatening military action would only escalate the crisis. The immediate worry is that Tehran will carry out its threat to withdraw from the nuclear Non-Proliferation Treaty. It is not a threat to be taken lightly, given that Iran has already caused the collapse of two years of talks with Europe on economic incentives for abandoning uranium enrichment, and has rejected enrichment deals offered by Russia. Foreign ministers of the five permanent members of the security council, plus Germany and the European Union, failed to agree on a strategy for dealing with Iran at a meeting in New York on Monday. China and Russia continue to resist any resolution that opens the way to UN-backed sanctions or military action. Mr Ahmadinejad's letter to Mr Bush may not have broken the ice with Washington, but it provides a less-confrontational backdrop to a visit to Asia by the Iranian leader this week that offers the opportunity for informal mediation. During five days in Indonesia, he will hold talks with President Susilo Bambang Yudhoyono and sign economic agreements before attending a meeting in Bali of the group of eight developing large Muslim countries. As the world's most populous Muslim nation, Indonesia is well placed to help as a mediator. And Jakarta has good reason for not wanting Iran, an important economic partner and fellow Muslim nation, to become internationally isolated like North Korea. Iran's letter to the US president has not paved the way for a solution. If one is to be found, it lies in stepping up the diplomatic efforts.