Tourism in Thailand is struggling now in the aftermath of over two months of political protests.
Thailand has some of the most beautiful beaches and some of the most fascinating cultural and historic attractions in Asia. But since September 2006 it has experience periods of political unrest that included violent protests and paralyzed air travel in and out of Bangkok – leaving large numbers of tourists stranded for days or weeks.
The current unrest dates back to a military coup in 2006 that forced then-Prime Minister Thaksin Shinawatra to flee the country. The most recent string of protests began in March after Thailand's Supreme Court found Thaksin guilty of abuse of power and seized his assets in Thailand. Police and the military fought occasional street battles with protesters who occupied parts of Bangkok until May 19.
While it is tempting to try and explain some of the political issues involved, that's not really what a travel blog is for. You can get some information from these sources: This chronology from CNN, an overview from the BBC, and these two pieces on different protest groups – the Red Shirts and the Yellow Shirts.
While calm has been restored for now, it's not clear that any of the political issues have been resolved and it's difficult to predict when new violence will break out.