While this isn't doctrinally Good Libertarian, there are real world reasons to make sure we have domestic capabilities in some industries, even if it lowers the overall economic output and/or makes products cost more to consumers.
We would want to keep an eye and make sure we don't get carried away with protectionism, or screw too many consumers, but globalism isn't always great even if it's 100% symmetric. And what we have isn't symmetric.