An historic day for Myanmar — or another false dawn? God knows there have been enough in the past 20 years.

Today, the UN Secretary General Ban Ki-moon flies into the country — at the invitation of the ruling generals 00 while, at Insein Prison, Daw Aung San Suu Kyi’s trial is set to resume.

Although there was little military presence around Yangon this morning, earlier in the week main roads and intersections were swarming with Myanmar Police Force personnel, clad in their grey-blue uniforms and wielding automatic weapons. Internet access speeds have already slowed to a trickle in the former capital.

On Monday, Myanmar’s Supreme Court rejected Daw Aung San Suu Kyi’s appeal against a ban on two of her four defence witnesses, clearing the way for closing arguments and sentencing. The government has successfully dragged out her trial — she is charged with breaching the terms of her house arrest, after American man John Yettaw swam to her lakeside compound — for more than seven weeks, pushing the issue further and further down the media agenda.

There is a lot riding on Mr Ban’s visit. It’s not surprising to hear groups like Human Rights Watch say anything less than Daw Aung San Suu Kyi’s release would constitute a “huge failure”. Mr Ban appeared confident last week when he made an appearance on American television, saying his previous visit to Myanmar, three weeks after Cyclone Nargis struck, saved 500,000 lives”.

But this is a slightly different ball game and Mr Ban knows it. The impasse between the government and Daw Aung San Suu Kyi is the biggest domestic issue that effects foreign relations. If she was released, it could be a watershed moment, despite the fact there are still another 2100 political prisoners behind bars.

In Singapore yesterday, he told reporters it would be “a very difficult mission” and admitted he would be visiting “under certain uncertainties” — a reference to the ongoing trial.

“I will try to meet with representatives of all registered political parties including Aung San Suu Kyi, that’s my hope. But I have to raise this issue with the Senior General directly, in person,” he said, according to AFP.

However, the generals are unlikely to acquiesce to his demands, particularly given Daw Aung San Suu Kyi’s two stretches of freedom in the past 20 years have both been disasters for the military government.

After being put under house arrest before the 1990 election, Daw Aung Suu Kyi was released in 1995 and immediately put Myanmar back into the international spotlight, calling for a ban on foreign investment, travel and — most controversially — international aid to Myanmar.

On her release in May 2002, Daw Aung San Suu Kyi began touring the country, ostensibly to view government development projects. At the same time, negotiations with the government broke down and, after her entourage was attacked near Mandalay by government-affiliated thugs, she was again placed under house arrest. This prompted the US and EU to strengthen economic sanctions, effectively crippling the local garment manufacturing industry.

With the 2010 elections coming up early next year, it’s unlikely then that the generals would release someone with the potential to do so much political damage.

Already the elections have become a thorny issue in the top echelons, with the military still yet to introduce an election law, despite the polls supposedly just six months away.

More likely, she will be convicted — she faces up to five years in prison — but with the term to be served under house arrest.

This result, while damaging for Mr Ban, would serve two purposes for the government. Daw Aung San Suu Kyi would of course again be out of the public eye again for a significant period of time but also, because of the criminal conviction, she would be unable to run for parliament in the future, under Myanmar’s 2008 constitution.

It will be interesting to see Australia’s response when the government hands down its verdict. It’s a common misperception that the country has wide-ranging sanctions against Myanmar; so far, only targeted personal financial and travel sanctions against government members, their families and some businessmen have been introduced.

The former foreign minister, Alexander Downer, said this was primarily because bilateral trade with Myanmar was so low — about $50 million in 2007. However, I suspect there are some advantages politically in not implementing tougher financial sanctions, as the US has done and the EU is now considering.

Last week, I noticed several Australian embassy staff, including the ambassador, in attendance at a farcical press conference held by the chief of Myanmar’s police force, Brigadier General Khin Yi, at which it was alleged John Yettaw was controlled by a “foreign organisation”.

The press conference was fantastic if you want to understand the mindset of a senior government official in a reclusive military regime that has been on the defensive for most of the past 20 years because of incessant international criticism.

“We are still investigating who or what organisation is managing, funding and masterminding [Yettaw],” the police boss said, before pointing out that he was arrested only about 30 yards from the residence of the US charge d’affaires, that country’s highest representative in Myanmar.

“There may be persons who are controlling Mr Yettaw, directing the scheme and providing financial assistance to him. We are still trying to expose those persons and organisations they represent,” the Brigadier General continued.

It’s no secret that the police are convinced Yettaw’s a CIA agent. However, the last time I checked, most crack CIA agents aren’t 53-year-old, overweight, diabetic alcoholics with serious mental problems.