The university students who organized a seminar in Thailand on the demise of dictatorships knew that one particularly sensitive topic had to stay off-limits: their own country.

Since overthrowing an elected government in May, this nation's military rulers have jailed opponents who dared speak out and silenced the rest with the threat of prosecution. They have censored the media, dispersed protesters and forbidden open debate over the nation's fate.

So when roughly 150 people showed up to attend the recent the latest in a series of talks Thammasat University called "Democracy Classroom," one weary student reminded all those present they should only discuss failed regimes — "please repeat after me, OVERSEAS."

A few minutes after it began, however, the event was cut short by police — triggering a rare public uproar from university professors nationwide over the expanding reach of junta censorship. The incident, the first of its kind on a college campus here since the coup, also underscored the fact that the deep societal tensions that have fueled a decade of political upheaval here are not being healed, but suppressed.

"The military says they want unity and reconciliation," said economics student Ratthapol Supasopon, who helped organize the Sept. 18 event at Thammasat's Rangsit campus, just outside Bangkok. "But how can that happen if we can't even talk to each other?"

Thailand has been beset by major bouts of upheaval since billionaire former Prime Minister Thaksin Shinawatra was deposed by the army in 2006. His ouster was part of power struggle that in broad terms pits the rural north against a traditional, military-backed elite based in Bangkok and the south.

That struggle helped fuel six months of anti-government street protests and sporadic violence that had paralyzed the administration of Thaksin's sister Yingluck Shinawatra, culminating in the May 22 coup.

Calm has been restored since then, and life in Thailand — on the surface at least — is once again utterly normal. Pristine beaches are filled with tourists. Glass shopping malls are filled with shoppers. Small-scale protests have fizzled. Yingluck, who was removed from office in a controversial court ruling just before the coup, has said almost nothing publicly; she was photographed smiling while grocery shopping during one outing.

But few believe the nation's troubles are over.

Our "society remains polarized, it's just that these views are being suppressed," said Prajak Kongkirati, a political science lecturer from Thammasat who was supposed to moderate the canceled talk last month.

"What we are doing right now is wrong and backward," he said. "When we shut down peaceful channels of communication like those in the media and academia, it will all end with street politics again someday."

After the Thammasat seminar was called off, 60 professors from 16 Thai universities declared in an open letter that if the fundamental right to exchange views cannot be respected, there is no hope that Thailand under the current leadership will ever "become a country that respects people's rights."

The coup leader, Prayuth Chan-ocha, has been unapologetic. He views criticism of the junta as divisive and unhelpful. He said any group that wants to hold such seminars must get approval first, so the content can be screened — because "if it's about democracy or elections, or how the government is today, this they can't discuss."

Ratthapol, the student, insists there was no plan to debate Thailand's own government and moderators would have cut off anyone who tried. But the junta clearly thought it would be tough to avoid discussing the elephant in the room — themselves.

"They wouldn't say it outright, but they thought we were going to talk about them," Ratthapol said of the soldiers who interrogated him for several hours at a nearby police station along with two other students and four professors, including one of Thailand's most respected historians, Nidhi Eoseewong.

The Hong Kong-based Asian Human Rights Commission condemned the incident and said it was "part of a broader pattern of intervention by the junta in public events organized by students, academics and human rights activists."

A few days after the seminar was shut down, another one, titled "Happiness and Reconciliation under 2014 Provisional Charter," was canceled on similar grounds at a university in the northern city of Chiang Mai. Also last month, the junta pressured an organization called Thai Lawyers for Human Rights to call off a presentation summarizing rights abuses in the country since the coup.

Authorities at Thammasat University, considered as a bastion of liberalism and progressive thought, have even censored themselves — banning the annual commemoration of the massacre of dozens of students during an Oct. 6, 1976, protest against the return of the nation's former military ruler, because it was deemed to be a political activity.

Prayuth has said academic leaders asked the junta how they are supposed to work with such prohibitions. He said there was plenty else to teach — like "the correct idea of democracy" or morality and the "12 core values of the Thai people" — a list he introduced as part of a junta campaign to "return happiness to the people."

Despite overthrowing an elected, democratic government, Thailand's junta promises to eventually restore "true democracy" — an official message repeated on billboards across the capital. So far, though, Prayuth has become prime minister, a rubber-stamp legislature has been installed, and the armed forces have put in place a temporary constitution that gives them sweeping powers.

Prayuth has said he hopes elections can be held in about a year. For now, the junta has asked the electoral commission and other agencies to give recommendations on how to eradicate populist policies from electoral politics. Analysts say that move is aimed at curbing the power of Thaksin, whose parties have dominated elections for more than a decade, even though he has lived abroad since 2008 to avoid a corruption sentence he says was politically motivated.

"Thailand is clearly not on a path toward democracy when free speech is censored, criticism is prosecuted, and political activity is prohibited," said Brad Adams, Human Rights Watch's Asia director. "The path that such repressive action leads to is dictatorship."

___

Associated Press writer Thanyarat Doksone contributed to this report.