The ‘free trade’ after World War II he referes to, was heavily stacked in our favor. With much of European and east Asian manufacturing centers bombed out, post-war US industry was poised at best advantage to fill the vacuum. Those glory days are gone. Free trade now simply means doing it all in overseas sweatshops and forced labor camps far from the prying eyes of OSHA, the EPA, or extortionist labor unions.
Because of that, the US pursued multi-lateral trade via the WTO.
But, as the US, overtime, lost that competitive edge, we shifted away from expanding multi-lateral to pursuing bi-lateral and regional trade agreements, as well a concentrating on our own back yard.
The first prez to pursue this with fast track authority was Reagan with Israel, the Caribbean Basin Initiative(which would eventually be replaced with CAFTA), and bilateral agreements with Canada and Mexico.
Under GWB Bush, the two bilaterals would become the trilateral NAFTA.
Under GW Bush CAFTA was completed and Chile was completed. Bush began the bilaterals with Columbia, Panama, and Korea and they were completed under Obama.
Keep in mind that Bush was not able to complete those 3 agreements because the dems blocked them because they thought the investor protections were excessive and Obama renegotiated them with more protections for labor and environment.