Fine .. say your country has a several years of drought and bad harvest. What happens then ? Do you trade then ?

Or .. lets say due to weather, your farmers can not grow enough oranges or some fruit which drives up local prices. Should only the richest people in your country get to eat fruits ?

Or you discover lithium deposits that your national industry can not use . Should you let that just sit there knowing it could make your province prosperous if traded.

Sure, you can trade but it is a choice. Claiming that free trade is universally good is saying that there is only one right choice - no barriers.