Free market propaganda has never been applied under equal circumstances. It is rhetoric used by capital to reduce or destroy regulations, labor, national sovereignty, etc. Western industrialized capitalist coubtries built their industry and infrastructure using tariffs to protect it, then turned around and demanded the opposite from other countries so that they would have to buy their products and sell whatever those colonizer countries wanted (at the time, usualky raw materials).

Now that other countries are ascendant, US-based "free market" capital is gladly re-embracing protectionist logic. It has only ever been about maximizing their profits. The "theory" of free markets tails capital, it isn't a science or even a valid line of thought.