The Temple of Preah Vihear was designated as a World Heritage Site in 2008 and, according to the Bangkok Post, Thai PM Abhisit states that delisting Preah Vihear as a World Heritage Site will defuse tensions:
Prime Minister Abhisit Vejjajiva is calling on Unesco to help defuse the border conflict between Thailand and Cambodia by delisting the Preah Vihear temple as a world heritage site and scrapping a Cambodian management plan for the temple.
Mr Abhisit said the two sides had come under pressure because of the listing and the management plan and this was the source of the problem.
It was therefore up to Unesco to ease the pressure stemming from the management plan, which is due to be tabled with the Unesco World Heritage Committee in June.
“I believe if Unesco manages to defuse tensions, the two sides would agree to hold talks without pressure. The two countries want their people on the border to live peacefully,” Mr Abhisit said.

Mr Suwit said yesterday the Foreign Affairs Ministry had told the Thai ambassador to France, as head of Thailand’s permanent delegation to Unesco, to explain the facts to Unesco authorities.
He said he was also preparing information to explain to the Unesco director-general the adverse repercussions the listing of Preah Vihear as a world heritage site had had on relations between Thailand and Cambodia.
Mr Suwit said the listing of the temple was not in line with the requirements of the World Heritage Convention in that the border land where the temple is located is not clearly demarcated and no proper management plan is ready.
Most importantly, the Hindu temple is on an overlapping border area claimed by the two countries and the listing should have been given approval by both Thailand and Cambodia, Mr Suwit said. He also said the Unesco plan to send a mission to inspect the Preah Vihear temple must receive consent from Thailand.
Mr Suwit warned that Unesco could be seen as lacking neutrality by not obtaining Thailand’s consent.
BP: Perhaps, Suwit should read the ICJ ruling that stated that Preah Vihear is located on territory which Cambodia has sovereignty over.
Atiya in an op-ed in the Bangkok Post puts the blame* on the World Heritage Committee:
I am sure Unesco’s World Heritage Committee must be very proud of its achievement at Preah Vihear. Two Thais and three Cambodians were killed and scores injured in the latest skirmish along the troublesome border shared by the two countries where the ancient ruin is perched – its perimeter seemingly straddles both countries.

What did you say? That Unesco director-general Irina Bokova has expressed her “deep concern” at the “sudden” escalation of border tensions? Of course, I have no doubt that Unesco must be troubled, even shocked, at the recent shoot-out and use of heavy weapons. It definitely could not have seen it coming, considering the history of amicability that the two countries have publicly displayed, at least not from the Unesco’s vantage position at Place de Fontenoy.

The report must be a cause for even deeper concern for Unesco. But then again, for the sake of the heritage issue it specialises in, why not leave the ruin in ruins? Leave the marks of destruction and traces of fighting, if there are any, the way they are so that the international agency can tell the world and the people who will surely throng to visit the place once it can be opened to the outside world what a precious heritage it is, that people from the two adjacent countries had to drag their heavy weapons and fight head over heels on how it would be managed.
UNESCO has named an envoy that it is sending for a preliminary/advance visit to arrange a visit to Preah Vihear who will come to Bangkok as per ANN:
WITH its mission to inspect damage done to Preah Vihear Temple during the border skirmish blocked, the United Nations Educational, Scientific and Cultural Organisation (Unesco) said on Friday that it would send a special envoy to Bangkok and Phnom Penh soon to pave the way for a visit to the temple.
BP: The reason for the visit to Bangkok is that Thailand opposes UNESCO sending someone to inspect Preah Vihear. Let’s imagine a parallel universe where Preah Vihear was not listed or is not delisted then the two sides would be able to hold talks without pressure. Perhaps, Abhisit may want to consider that the Cambodians would be upset if they were not able to list Preah Vihear as a World Heritage Site.
BP would argue that the issue of Preah Vihear is a much more emotive issue on the Cambodian side than the Thai side. Does Abhisit really believe that if Thailand had been able to block the listing of Preah Vihear or that if Preah Vihear is delisted that the Cambodians would be happy and there would not be a domestic political problem in Cambodia? If Preah Vihear was delisted, would the Thai parliament approve the JBC minutes? Supalak in The Nation notes on the lack of progress on border demarcation:
Thailand and Cambodia have a joint boundary committee (JBC) and a memorandum of understanding (MOU) signed since 2000 to handle land boundary demarcation.
However the JBC has not worked properly for a period of time since its previous meeting in April 2009 as Thai parliament has not yet approved its minutes of three previous meetings to give nod to the body to go ahead the survey and demarcation tasks.
Having JBC to settle the boundary conflict with Cambodia is an uphill task for Abhisit’s government as nationalists protesting on streets and working in the parliament would not allow the government to implement the 2000 MOU as they feared Thailand could lose territory to Cambodia.
Abhisit-once friendly People’s Alliance for Democracy, which has been camping near Prime Minister Office since last month, wanted the government to scrap the MOU and used armed forces to remove Cambodian people, troops and property out of the disputed area.
Cambodia’s JBC chief Var Kimhong rejected a Thai proposal to call a JBC meeting later this month saying the bilateral mechanism cannot resolve the issue.
Meanwhile, Thailand’s JBC chief Asda Jayanama did not focus on boundary work but was busy with lobbying the Unesco in Paris to have the UN cultural body stayed away from the Preah Vihear.
BP: The PAD and other nationalists are not saying delist Preah Vihear and we will be satisfied. Yes, they would be happy with the delisting, but they want the MOU scrapped and the Cambodians forcibly removed. The Democrats are afraid of the PAD and the nationalists so would they really have called on parliament to vote on the JBC minutes now? BP doesn’t know how Abhisit can say with a straight face that delisting Preah Vihear would defuse tensions. The PAD and the nationalists would still not be satisfied and the Cambodians would now be mad.
*One assumes Atiya is not trying to be ironic, but if she is the commenters aren’t picking up on it.