The presence in international waters off Myanmar's coast of French, US and British naval vessels loaded with thousands of tonnes of aid adds the lustre of possibility to the vision.

The sober reality, however, is far more complicated.

Seasoned UN officials with long experience of air drops in African trouble spots say carrying out action unilaterally is exceptionally difficult.

Even putting aside the thorny question of sovereignty - the junta would almost certainly see it as an act of war - the logistics are tough.

'Imagine dropping buses on villages from 300 feet [90 metres] ... that is effectively what you are doing,' one UN relief veteran explained. 'Airdrops are an immensely difficult and dangerous task ... if you are not careful, you kill the very people you are trying to save.

'For them to work safely and effectively, you need teams on the ground to map out clear drop zones and organise distribution. You must avoid a free-for-all as the stuff lands to avoid the booty being snaffled by greedy black marketeers, or worse, the regime.'

In short, the experts warn, little - for the moment at least - is likely to happen without some kind of green light from the junta.

In that regard, anticipation is building ahead of an urgent mission to Yangon and Naypyidaw starting tomorrow by UN Secretary General Ban Ki-moon.

Facing one of the major tests of his tenure, Mr Ban has been expressing intensifying concern at the junta's inaction. He has plenty of ammunition. UN sources say he has been given internal reports detailing extensive obstruction from the generals.

This ranges from difficulties in obtaining visas for key staff now waiting in Bangkok, other foreign experts being held within Yangon, and problems in clearing food and medical aid for distribution after it arrives at Yangon International Airport - unprecedented problems in the history of humanitarian relief.

Senior UN officials were given a jarring warning from the generals on Sunday night as they mapped out plans for the week. Just as they appeared to be getting co-operation at the end of last week, one senior official put the brakes on.

'The emergency is over,' the official told them, reflecting the widening gap between an ever more desperate reality and the view from Naypyidaw. 'There is no need to rush ... the effort now is rebuilding, not relief.'

The bureaucracy, the aid workers now fear, will only escalate - despite increasing fears of a rising death toll from starvation and disease.

Mr Ban is to meet junta supremo Than Shwe, a figure now widely seen as increasingly paranoid and isolated. Over the weekend, the multimillionaire general emerged from his lair in Naypyidaw to visit model relief camps and get briefings from his ministers in Yangon.

It is unlikely to be a smooth meeting between the pair. Senior General Shwe has repeatedly refused to take Mr Ban's calls.

The session will follow this week's Association of Southeast Asian Nations meetings in Singapore on the crisis and a compromise deal is now in the offing.

Underpinning the diplomacy is the mystery of precisely why the junta is so sensitive to foreign involvement, and the delta itself.

Many analysts believe the generals viewed with alarm the way international relief efforts after the 2004 Asian tsunami opened up the Indonesian province of Aceh to reform.

Then there is the junta's habitual desire for ultimate control. The military has been in unbroken power for 46 years, refusing to accept the democratic opposition's election victory in 1990. Paranoia reigns supreme, and the generals see themselves as uniquely qualified to govern.

The delta itself is another factor. Once uninhabited, it was developed by British colonial rulers into the nation's rice bowl. That role continues.

Rice is considered a highly strategic commodity for the junta, and private-sector reforms in other areas have yet to reach rice production. The junta keeps a tight rein on production, storage and distribution. It controls exports, doling out licences to favoured Myanmese businessman in exchange for other favours.

In several weeks' time, the year's second crop must be planted and the junta wants people back on the land to complete the work. It also wants them home to complete a constitutional referendum on Saturday.

In that regard, the curtain of checkpoints stopping foreigners leaving Yangon also serves to keep a tide of refugees from leaving.

The regime seems unlikely to open up the delta any time soon. And, for the moment, the dogs of war remain firmly on the leash as the diplomacy continues.

Our correspondent's identity has been concealed for safety reasons