No, obviously protectionism is only part of the various factors that lead to the dominance of western economies, but it was crucial as a contributing and facilitating factor.
The usual conception that free trade was born in the British Empire and in the US is ridicolous. The US and Europe always maintained policies of protectionism and still do, because they were crucial to their power. (Reagan, the great free trader, was the most protectionist president in post war history) Free trade, on the other hadn, was imposed upon the poor and defenceless, and indeed, the whole field of free market economics and laissez faire were just intellectual fields developed with elite interests in mind.
Yes, our agriculture subsidies have very easily made poor farmers in foreign countries better off, right? And the people of the U.S. benefit so greatly from these subsidies that we can afford to destroy excess food. Hurrah for protecting the American farmer! right?
Or perhaps protectionism could be engaged without negative serious consequences from other nations when there was ample supply of resources to take, not trade, from other "less civilized nations". For instance, almost every western nation engaged in some form of colonial exploitation well up into the 1950s. Western nations surely competed against one another in producing goods and enacting tarrifs but no western nation was bound by the constraints of a limited supply of resources or lack of area to expand in to. They simply plucked resources for almost free from places "less civilized". Until the resource rights and sovereignty of other nations were respected the supply curve could be shifted right to match any protectionist policy.
Surely Japan was protectionist pre WWII when they colonized integral of the pacific rim. and surely they were protectionist post WWII when they received capital for free from the United States. And surely their protectionism is helping their economic growth right now by, oh wait a sec, it isn't. Yes, the Japanese are wealthy comparative to other people in other nations but they've barely had any economic growth since the late 1980s. Protectionism has really helped the Japanese right? I mean they went from being a colonial power in their region, to being a world power, to being decimated, to being a world economic power, to being a stagnant economic power. and honestly, Ikeda LIBERALIZED TRADE, that is, made way for more free trade during his term. At some point a country can't play in the bigs and be protectionist without harming themselves, as Japan showed. That's right Princeps, trade actually liberalized in Japan post WWII within the 1960s. To attribute post war Japan's success to protectionism would be ignoring that the level of protectionism decreased in Japan following WWII. The retort to this observation might be that protectionism allowed them to get to the point they were at but I argue that consequence free exploitation allowed this to happen.
on the more fundamental and philosophical level, isn't holding 3rd world countries over a barrel for the benefit solely of a 1st world country protectionism? Isn't that what happens when you limit where a 3rd world country can fence their goods in retaliation for protectionism they enforce? Isnt that what happens when a 1st world country doesnt liberalize trade and prevents the ability of 3rd world countries to receive NCOs? Why are you so eager to deprive people in the 3rd world with limited resources the opportunity to compete by excusing 1st world protectionism? This is central to an observation in Ha Joon's essay I made; does a country even have the resources and capability to engage in international trade and protectionism at the same time?
After reading Ha Joon's essay I can't say that I am convinced of his explanation that protectionism provided the basis for economic growth in the western world. The examples that he provided for countries that used protectionism were either not confined to limited resources or factors of production in similar ways to countries now, were given technology/capital and resources as a proxy in wars with wealthier nations, and had already established forms of national identity and institutions of government. I think an interesting thought in his essay has to do with intellectual property though. Isn't copyright and IP just a form of protectionism? The flow of information freely is the antithesis of protectionism.
Another problem I see with a lot of this is semantics. Is regulations of foreign businesses within domestic borders protectionism or simply business regulation? What is truly free market and what is truly protectionist? I think tariffs, subsidies, can be ruled as being protectionist but is government failure to adequately regulate a foreign business while no domestic alternative or no international competition existing really free market? Is the IMF free market or simply a one way pro american trade organization? Lets not confuse predatory behavior as being the hallmark of any one school of thought.
In summary, while it may be nice to think that protectionism is a stepping stone to economic development and liberalized trade later down the road, it is not without greater costs to someone else in the world until that liberalization happened. Africa and Latin American are still paying the price for European and American protectionism.