Rob. Not sure of your point. Could you expand?
Yes, sure. If a government makes a bad decision over purely internal matters, all the country needs do is wait for the next general election and vote that government out, and make changes to 'correct' the situation. That is a thing within the remit of each country's government and citizens; it's an internal matter that can be resolved internally.
In matters such as membership or otherwise of international bodies, decisions made
and applied by one government cannot be reversed by the election of another government of that country should an error be perceived to have been made; it depends on the rest of the independent countries' governments involved and affected by that dubious decision, and how positively or otherwise they feel disposed towards the 'sinner' country after the fact.
In the first case, new elections can change the landscape and clear away mistakes, so a smallish majority is perhaps enough to be legitimate.
In the second instance, I believe that it requires a far more substantial majority to truly represent the nature of a nation, because the decisions being made cannot be reversed in five or so years by simply changing the colour of the next government. In other words, any decision made is pretty much permanent, whether it's a good or a bad one; no second chances.
In fact, I think that a referendum should never be used because it puts complex matters in the hands of people who generally do not have the equipment to deal with the choices properly. I certainly do not believe that I would be the best person to make such decisions, if only because I have definite personal reasons to wish to maintain the status quo. That colours my perspective. I have lived in a variety of countries and consider myself far from totally dumb. Yet, I'd hate to be responsible for the future well-being of any nation, a responsibility that would appal me; I just don't have the knowledge of the detail, the inside track, to formulate the best decisions, and by gum, neither does 99.99% of the rest of the herd. That's why we employ politicians, at least, in theory, and hope that by experience at the coalface they gain the understanding needed for the job.
Rob