Former Prime Minister Thaksin Shinawatra returned to Thailand on Tuesday after spending 15 years in exile.  

The 74-year-old politician was immediately arrested and the Supreme Court sentenced him to serve eight years in prison on old graft charges.

For his most ardent supporters, however, it was an emotional moment.

"No matter which land he's in, wherever he goes, I love only Thaksin and always have," Boonying Pim-Makaed, from the northeastern province of Loei, told the Reuters news agency.

"I'm so glad that he's back."

Was there a backroom deal?

Just hours after Thaksin landed in Bangkok, Thailand's capital, the Thai parliament confirmed business tycoon Srettha Thavisin as the Southeast Asian nation's next prime minister.

Srettha heads a broad alliance led by Pheu Thai, a party associated with Thaksin.

The coalition includes parties linked to the military, which toppled both Thaksin and his sister Yingluck as prime minister. 

The development has led to speculation that there may have been a backroom deal between Thaksin's camp and the powerful monarchical-military establishment to cut his sentence short. 

Pheu Thai has denied such an agreement.

Mark S. Cogan, associate professor of peace and conflict studies at Kansai Gaidai University, said Thaksin's return to the political arena is a "lose-lose" move for his party's credibility.

"The narrative of a power-hungry Thaksin is terrible news for Pheu Thai as it also sends a morally-bankrupt message to longtime supporters that his values and principles can be corrupted by making a deal with the devil, the same people that not only drove him from office, but forced him into exile," he told DW earlier this month.

Who is Thaksin Shinawatra?

Thaksin, an immensely wealthy ethnic-Chinese business tycoon, has been a dominant figure in Thai politics for over two decades.

He became prime minister in 2001 after decisively winning the elections held that year. 

Thaksin cultivated a public image as a champion of the poor and won the loyalty of millions of Thais — particularly those living in the more populous but relatively poorer northern and northeastern regions of the country — with policies aimed at promoting rural development and health, among other things.

But his leadership proved deeply divisive and aggravated the nation's deep fault lines, pitting the urban against the rural population, the rich against the poor, and the northern and northeastern regions against Bangkok and the south.

The conservative establishment — comprising the army, the judiciary, the bureaucracy, the Bangkok elite and the royalists — saw his rule as corrupt, authoritarian and a threat to the Thai social order.

They also perceived him as a threat to the nation's revered monarchy.

In September 2006, the military pushed Thaksin out in a swift and bloodless coup d'etat while he was in New York for a United Nations meeting.

Thaksin found himself fending off multiple criminal cases in the aftermath of the coup, including charges of corruption and tax evasion. He fled Thailand in 2008 to avoid imprisonment.

Still, Thaksin has remained powerful and continued to enjoy robust support among sections of the population, particularly the rural poor.

And voters kept electing governments loyal to him, in both 2007 and 2011.

Then, in 2014, the military staged another coup to oust the then Pheu Thai government led by Thaksin's sister Yingluck.

Tightening grip over levers of power

In the following years, the military has enforced new laws to silence dissent and put in place a new constitution to ensure that the royalist establishment has a tight grip on all levers of power.

Under the constitution, for instance, both houses of Parliament — the 500-member House of Representatives as well as the military-appointed 250-seat Senate — vote together to elect the prime minister.

And senators, like the army, see themselves as guardians of traditional conservative royalist values.

This resulted in a political deadlock following the parliamentary elections in May.

The outcome of the election was a blow to the military and the ruling government under outgoing Prime Minister Prayuth Chan-ocha, with the two main opposition parties — Thaksin's Pheu Thai and the Move Forward Party led by Pita Limjaroenrat — securing the most votes and seats.

Even though Pheu Thai had been expected by many to win the elections, Move Forward delivered a surprise by securing the most seats.

Nevertheless, their combined votes fell short of the 376 votes in parliament needed to name Thailand's next prime minister. 

Move Forward pledges to reform the nation's strict lese-majeste laws and tackle powerful state-owned enterprises and monopolies also spooked the conservative elite, prompting military-appointed senators to block party leader Pita's bid for premier.

Thaksin 'won't do any good'

Political science professor Siripan Nogsuanat from Chulalongkorn University believes that Thaksin's return "won't do any good" for the country's political future.

"I think he has the right to be back. The impact of his coming back for me signifies a reflection of a compromise between Thaksin and former adversaries based on new perceptions towards the Move Forward [Party] as the bigger threat to the Thai traditional elite," the professor said.

"The signal of him returning is an attempt to show the Senate he is now with the conservative force" and could curb the rising popularity of the Move Forward party, Siripan told DW.

Edited by: Wesley Rahn