You are correct. People need to file. Earned income from salary, investments, rental income, etc, may need to be paid in Thailand following taxes paid in the home country. That being said, many types of income are protected by treaty. The USA prohibits by treaty, sections 20 and 21 specifically, Thailand from ever taxing Social Security, military retirement, veterans benefits, state and federal pensions. Most Americans living in Thailand receive the lion-share, if not all of their monthly income, from the nonassessable income from the sources enumerated above. Very few Americans will be impacted. Those with IRA's, 401K's and actual earned income, I agree, will be. That being said, you are a Canadian national. Why are trying to be an expert on the USA/Thailand Dual Taxation Agreement Treaty?
Americans need 0 advice from unknowledgeable Canadians.
SSA, military, state and federal pensions, including veterans disability benefits, are NOT assessable under the specific sections 20 and 21 of the DTA Treaty between the USA and Thailand, regardless of whether these benefits are taxed in the USA or not. Read the treaty. Thai bureaucrats can NOT arbitrarily add to, change, modify, or ignore the terms set out in the DTA treaty. The USA and other western nations would jump down Thailand's throat with both feet if the Thai establishment tried to arbitrarily void sections of any established DTA treaty, leading to potentially severe financial and economic consequences for Thailand. Treaties are not a one way street. That being said, you are free to espouse your views. I, for one, will ignore them, and NOT at my peril.
I get it. Now you are in denial that you rebuke or criticize anyone. You are the one who began all of this by referring to Frank as a Troll and implying the other gentleman was stupid with your "duh" comment. Like I said...you have no problem dishing it, but you just can not take it.