You misunderstood. The author described our current "free trade" model which is "mercantilism", but he did not describe it as "desirable". He pointed out the long term detriment that will result.
With unrestrained mercantilism, the costs of international trade are socialized through increased taxes on the working class citizens, and through increased national and consumer debt, which will eventually have to be paid by the citizens and their descendents. The short-term benefits of our mercantilist free trade model are restricted to a relatively small number of non-productive self-anointed elites.
It is the global socialists who are pushing for the destruction of the US economy through anti-American free trade agreements.
We disagree. The Japanese have a mercantile economy, not the US. You should really look up the definition of "Mercantilism" in an economic or plain dictionary, before you go any further.