I've heard a lot of people say the problem with free trade is that it only works when both countries are allowing trade. That's wrong. For example even if China sells to us but doesn't allow us to sell to them, it still benefits us (and hurts China).

Suppose in the US, a strange new volcano started spewing perfectly formed free high grade steel. Should the US ban the free steel because it would hurt US steel manufacturers? Or use that steel to make other products cheaper, like cars for example?

If a foreign country sells us cheap stuff we should say thank you. Not ban it.