The White House calls it the "pivot" towards Asia - President Barack Obama's strategic refocus on engaging fast-growing Asian nations, away from the preoccupation of the previous decade with war and terrorism in Afghanistan and the Middle East.
His choice of destinations for this, his first overseas trip since being re-elected - Thailand, Burma and Cambodia for an Asean summit - reflects something else.
"We are not just rebalancing towards Asia," said Mr Obama's National Security advisor, Thomas E Donilon, in a speech this week.
"We are also rebalancing our efforts within Asia. We had been heavily invested in North-east Asia for lots of historical and other reasons, but we have really focused here in a renewed way on South East Asia and Asean."
'Outpost of tyranny'
It is the six-hour visit to Burma which will stand out, the first by a sitting US president, and a remarkable event in a country that until last year was a virtual pariah state because of its terrible record of human rights violations and military misrule - an "outpost of tyranny", according to former US President George W Bush.
US officials say the goal of the visit is to show support for the reforms undertaken by President Thein Sein, and to explore areas in which the US can support the development of democratic practices and institutions.
Another goal - an unstated one - is to claw back some of the influence China has been able to exert over Burma during the years of isolation and sanctions.
That is something even old-school Burmese military men will approve of. Their country has a historically uneasy relationship with its giant northern neighbour, and the high dependence on Chinese investment and military technology has been a source of discomfort.
The Obama visit has alarmed a number of human rights groups, though. His officials say he will raise the issue of political prisoners, army abuses, and the need for deeper reforms, as well as the communal violence in Rakhine state.
But campaigners are asking why such an important, symbolic visit had to happen so soon, before the reforms, which started so unexpectedly last year are fully implemented and apparently before Mr Obama's people had secured any concessions from the Burmese government.
The government did announce an amnesty for 452 prisoners this week, in what it termed a "goodwill gesture", but did not include any of the estimated 280-330 political detainees documented by human rights groups.
"The fact that the Burmese government just released a bunch of prisoners, but apparently neglected to include any political prisoners, is hardly an auspicious start to this visit," says Phil Robertson, from Human Rights Watch in Bangkok.
"In fact, it leaves the impression that now that Nay Pyi Taw has achieved the prestige of a US presidential visit, they may be backsliding on their commitments to release all political prisoners."
It is not clear yet whether the US delegation will go to Burma armed with a list of political prisoners, or whether they will be able to secure any more releases.
To come away empty-handed would open Mr Obama to the charge that he rushed into Burma without securing concessions in return for the prestige of a first-time presidential visit.
In other ways, his schedule has been calibrated to acknowledge the authoritarian legacy, which still hangs over Burma.
He is not going to Nay Pyi Taw, the vast new capital constructed in secrecy by the last military government, which is normally the designated venue for diplomatic meetings.
In an unusual concession, President Thein Sein will travel down to Rangoon to meet him. It is thought this was a request of Aung San Suu Kyi, whom Mr Obama will meet at the lakeside home in Rangoon where she was detained for 15 years.
Apparatchik to reformer
He has also chosen to deliver a speech at Rangoon University, a dilapidated, old campus which was once the most prestigious academic institution in the country, but was emptied of undergraduate students by the military after the mass protests of 1988.
The university is still seen as a symbol of dissent, and the new government has promised to restore its academic life. Some hasty cleaning and painting has been going on in recent days to make it suitable for a US president.
The changes in Burma over the past year have been so sudden and so unexpected there is still a great deal we do not know about them.
We do not know whether they are being driven largely by President Thein Sein, once viewed as a cautious apparatchik of the old regime, and his "kitchen cabinet" of reformist ministers, or by other forces.
We still do not know what influence former military ruler Than Shwe wields over the new government.
No-one is even sure on what terms he handed over power; his own, or was he pushed?
The armed forces remain a very powerful player, allocated a quarter of the seats in the new parliament, unaccountable for their actions, and with significant business interests.
Given that, Mr Obama seems to be taking a gamble that he is backing a winning horse without being sure yet whether it can finish the race.
Four years ago when he was first elected, he made engaging with America's adversaries one of his principal foreign policy goals. His efforts reaped little reward in Iran, North Korea and Venezuela.
Only Burma has shown promising results.
"We're not naive about this," said Thomas Donilon. "We're absolutely aware of the dangers of backsliding. But this really is a moment we didn't want to miss."