Despite a return of political stability after the May 2014 coup, Thailand is kept near the bottom of an Asian political risk index due to its "fundamental divisions" and concerns over the king's health, a research unit of Fitch Group said.
BMI Research gave Thailand the short-term political risk score of 57.9 out of 100, ranking it 31st of the 37 Asian economies it covers, ahead of only Myanmar, East Timor, Fiji, Pakistan, Papua New Guinea, Nepal and Afghanistan.
While the government has successfully restored peace since the coup, it is hard to gauge whether this could be "calm before the storm", BMI wrote in its country review released on Tuesday.
"Indeed, none of the underlying divides between the pro-Thaksin [Shinawatra] 'red shirts' and royalist 'yellow shirts' have been addressed, only suppressed.
"It is not clear if Thaksin's influence on Thai politics has waned, or if it is just dormant and there remains a risk that he could mobilise resources to ignite a red shirt-led pro-democracy resistance in the provinces."
The criminal trial of Ying luck for neglect of duty in the rice pledging programme could be a potential trigger for such a movement, it predicted.
BMI Research also factored in the closer diplomatic ties the junta has forged with China as another reason.
"The risk is that Thailand's relations with the west deteriorate further as a return to democracy pushed further and further back."
While BMI ruled out the possibility of sanctions, the US could scale back its strong military ties with Thailand.
Fitch Group's research unit also cited potential instability in the South China Sea as another risk factor.
"China's push to form closer ties with Thailand is partially driven by this dispute, with Thailand being a rare country within Asean that is not contesting territory.
"This will make it difficult for Asean to put together a united stance against China regarding its territorial claims, and may create frictions within the Asean community."
BMI provides macroeconomic, industry and financial market analysis covering 24 industries and 200 global markets.