@dljohn-- You've touched on one of the reasons why international trade is controversial.
Have you heard of the term comparative advantage in international trade?
A country is said to have a comparative advantage over another when it can produce a good at a lower price. Comparative advantage forms the basis of international trade. When countries sell goods they have a comparative advantage in, everyone benefits.
Not only does this allow consumers like you and me to get goods for cheaper, but it also increases the variety of goods that are available to us. Meanwhile, the economy also grows and our quality of life increases in the process.
The worker who gets laid off from his job won't be very happy about it. For this reason, some governments impose high tariffs on certain goods to protect that industry. So even though this can seem like a disadvantage, governments can avoid it if they want to.