Forner Asean secretary-general Surin Pitsuwan swopped a regional platform for a national one this year, returning to Thailand after five years helming the regional organisation.
Now heading a think-tank backed by the opposition Democrat Party, he says his main task is to devise long-term policy proposals for the country with a specific focus on education, corruption and the economy.
The Harvard-educated, one-time deputy Democrat Party leader was considered one of Asean's most eloquent advocates, and this has raised expectations that he might bring a little of that star power back to his old party, or give a lift to Thailand's divisive political scene. But he has chosen to stay above the political fray - for now - while still remaining very much in the limelight.
Dr Surin, 63, oversaw Asean as its global profile surged, helping to prod Myanmar along the path of reform when it was still a global pariah, and proving an indefatigable champion even as member states squabbled over territorial claims in the South China Sea towards the end of his term.
At a recent forum organised by the think-tank, called the Future Innovative Thailand Institute, the straight-talking former foreign minister shared his exasperation over the revolving door of Thai administrations he had encountered during his term at Asean. In the five years he spent there, Thailand saw five prime ministers, he noted.
His role now, he said, was to ask "difficult fundamental heavy questions" about his country, which critics have flagged for fiscal indiscipline and corruption, as well as an outdated education system.
But he is not plunging into the hurly-burly of Thai politics, at least for now.
He told The Straits Times: "When I returned there was a lot of expectation for me to recycle back into public life. I'm not sure if I am ready for contentious partisan politics."
However, he added: "A lot of people are reaching the conclusion that this country needs some new answers to solve old problems. I think there is a need for someone to be leading them to think and to ask those important questions."
Analysts say Dr Surin, a Muslim statesman in Buddhist-majority Thailand, still commands considerable respect, especially in his hometown in the southern province of Nakhon Si Thammarat, where he was a Member of Parliament for seven terms.
Dr Kitti Prasertsuk, who heads Thammasat University's Institute of East Asian Studies, said: "He's very popular among the people, not just among elites but also the grassroots."
As a testament to his appeal, his name was used by supporters of the ruling Puea Thai party to encourage Bangkok residents to vote for its candidate Pongsapat Pongcharoen during the March 3 gubernatorial election.
Its convoluted argument: If incumbent Democrat candidate Sukhumbhand Paribatra lost, Democrat leader Abhisit Vejjajiva would have to resign, paving the way for Dr Surin to take over.
Dr Surin rubbished such talk back then, and Mr Sukhumbhand triumphed in the polls.
What is more, it may be hard for Dr Surin to fend off younger rivals for party leadership and deal with a polarised electorate.
"He will find it increasingly more complex to return to domestic politics," said Chulalongkorn University political scientist Panitan Wattanayagorn, who used to be a spokesman for the former Democrat-led government.
Ironically, Dr Surin's absence from Thailand may bolster his already considerable clout. While he was gone, Thailand was wracked by debilitating protests from factions either aligned with or opposed to the fugitive but powerful former prime minister Thaksin Shinawatra. Being away, Dr Surin was not closely associated with the bitter rivalry.
He told The Straits Times: "Being away for so long, there is a lot of goodwill."