Trade between two countries is likely to be mutually advantageous except when?

Trade between two countries is likely to be mutually advantageous except when one country has a significant comparative advantage in all goods, leading to a lack of incentive for the other country to engage in trade. Additionally, trade can be detrimental when it results in significant job losses or economic disruption in one country, or when trade policies are heavily protectionist, creating imbalances and tensions. Furthermore, if the countries have vastly different regulations or standards, the benefits of trade may be undermined.