According to Wikipedia:
Paris was soon consumed with riots, chaos, and widespread looting. The mobs soon had the support of the French Guard, including arms and trained soldiers.
... By late July, insurrection and the spirit of popular sovereignty spread throughout France. In rural areas, many went beyond this: some burned title-deeds and no small number of châteaux, as part of a general agrarian insurrection known as "la Grande Peur" (the Great Fear). In addition, plotting at Versailles and the large numbers of men on the roads of France as a result of unemployment led to wild rumours and paranoia (particularly in the rural areas) that caused widespread unrest and civil disturbances and contributed to the Great Fear.
This could be the scenario for Bangkok and Thailand.
Some highly abbreviated speculations on how it got this way:
1. The yellow shirts (PAD) seized the airport in 2008 and forced the collapse of a pro-Thaksin government. The yellow shirts were hardly punished for their actions.
2. The red shirts are now doing to Bangkok what yellow shirts did to the airport.
3. The current pro-PAD government believe that the yellow shirts are negotiating from bad faith. From WaPo: "Red shirt demonstrators, it seemed, had forced the Thai government to call an early election. But that deal foundered on last-minute demands from leaders of the red shirts."
4. This has hardened the current government's stand. From the BBC: "Thailand's government has rejected an offer of mediated talks with red-shirt protesters aimed at ending an increasingly violent confrontation." They have begin ominously to label the more militant faction as terrorists: "The situation has escalated and become violent with armed groups and terrorists attacking the government, officers in the field and civilians," cabinet minister Satit Wonghnongtaey said in a televised news conference. ... The government accuses hard-liners within the red camp of using women and children as shields. At a news conference on Tuesday the military showed footage of what it said was a protester holding a baby over a barricade.
5. It has also hardened the government's response. From the same BBC link: The red-shirts, meanwhile, accuse government troops of firing indiscriminately on them, although the army said troops were firing live rounds only in self-defence. They have also been accused of assassinating Maj Gen Khattiya, known as Seh Daeng (Commander Red). Moreover, they have also rejected UN mediated talks.
6.Meanwhile, the conflagration spreads: Protesters roaming the lawless streets of a strategically important neighborhood near the protest zone threatened to set fire to a gasoline truck as bonfires, some from piles of tires, sent large plumes of black, acrid smoke into the sky. .... Security forces armed with assault rifles were deployed in greater numbers across the city after many firefights, including a nighttime grenade attack on the five-star Dusit Thani Bangkok Hotel, a landmark in the city. The attack and a subsequent prolonged gun battle suggested that Thai security forces were up against more than just protesters with slingshots and bamboo staves. Protests have spread outside the capital with a military bus set afire in the northern city of Chiang Mai and demonstrations in two north-eastern towns in defiance of a government ban.
7. While some may see this the eclipse of the influence of the king, I find it hard to believe that the current government actions do not have the tacit and implicit support of the Privy Council.
What may happen:
1. Both sides ratchet up:
The government declares Thaksin a terrorist and makes a "with us or against us" speech. Elite military troops fan out across the country to target red-shirt leaders. Thaksin is also targeted. Heavy artillery and the air force are used to target red-shirt encampments. Rank and file who are pro-red shirts abandon the military and fight an insurgency within Bangkok and the country. They target the elite and the members of the Privy Council including ransacking and looting their property. A civil war breaks out and given the numbers this is a war that the current government will eventually lose on the international public relations arena but can only win domestically with sufficient violent force. A autocratic government is established.
2. The best outcome for the red-shirts:
A compromise is reached where some UN monitoring is accepted. The UN will monitor the November elections originally proposed as well as hold an inquiry into the events of April 2010 where red-shirts died in a demonstration. The outcome of this election is a forgone conclusion.
3. The best outcome for the yellow-shirts:
Continued use of force to arrest red-shirts and imprison agitators is successful enough to tamp down revolutionary fervor. Thaksin is branded a terrorist and all financial assets are frozen. All his advisors currently in Thailand are arrested, tried and jailed. An election is held where the result is favorable to the yellow-shirts. The results are known prior to the election being held. Red-shirt leaders continue to be arrested and jailed.
4. Is there a compromise solution?
Red shirts withdraw from Bangkok and the current government ceases police and military action. The original November election is held as originally proposed. Some UN monitoring is allowed for the elections but no UN investigation into the demonstrations is initiated. Both sides agree to abide by the outcome of the elections but with a lot of pre-conditions with regards to the candidates that parties are allowed to field. The result will be candidates that no one really likes and some kind of hung parliament that muddles along for years. Think Phillipines.
In cases 1 and 2, we will see capital flight from the urban elite as well as private investors.
Are there lessons for Thailand from:
1. Sri Lanka? The majority Buddhist Sinhalese finally defeated the Tamil Tigers after almost 30 years of civil war. Both sides have been accused of human rights abuses despite the fact that Buddhism has been characterized as a largely peaceful religion. Is such a civil war and human rights abuses in the future for Thailand? Alternatively, consider what the current Sri Lankan government is doing in reconciliation with the northern Tamils. Is the same rapproachment toward the Northern and Northeastern Thais from Bangkok possible?
2. Italy? Will a return of Thaksin Sinawatra be possible? If so will he be another Silvio Berlusconi - essentially a corrupt government official using the state to line his pockets? The sale of Thaksin's Shin Corp has already proven beyond a shadow of a doubt that he is not above using the state for personal purposes. In line with Berlusconi, he had curried favors with politicians using money and he had promoted loyalists with whom he has done business with into government positions. (See this for a legacy of Thaksin's rule.)
This is the end of Thailand as we know it.
Update (5/27): Looks like Thaksin has been declared a terrorist.
One scenario that I did not consider above was that the red-shirts are being used by Thaksin's group in a bid to bring him back to power - in which case, see the Italy comparison. In this scenario, any reconciliation attempt by the current government whether it continues to hold power or not will be undermined by the Thaksin loyalists. Even a yellow shirt government that tries to spread the distribution of wealth more equally would not be trusted. Even as it tries to gain the trust of the red-shirts, its attemps will be undermined by propaganda. The Thanksin loyalists may carry out insurgent attacks which will then be blamed on the current government.
Some other ruminations here.
Is there a hopeful solution?
Perhaps the best outcome would be the "charismatic" leader outcome. Some one incorruptible (and Thai politics has always been corrupt) that rises above the yellows and the reds and lays down the law Lee Kuan Yew style. It had been my hope that Abhisit would be the one (and he still could be the one) but right now he strikes me as a bureaucrat.