> The promise of globalization was primarily about improving economic efficiencies, not liberalization.

At the time, it was presented to the public as both. Inseparable. Liberalism was development. Development was liberalism. Besides the Communist Bloc, whose actual degree of development was rather questionable, no significant counter-examples existed at the time, and most recent political liberalizations had been followed by drastic and rapid economic growth as the country integrated into global capitalism. So it was a logical enough hypothesis. It was also the guarantor of global peace, supposedly.

This is a quote from Stephen Harper, former Prime Minister of Canada from a speech he gave at the United Nations in 2014 extolling the virtues of free trade:

> [...] We also believe that they are the necessary foundation for a better world for more people, necessary for prosperity, and with prosperity comes hope, and with hope, the greater inclination of free peoples everywhere to find peaceful solutions to the things that divide them.

> Indeed, we believe that freedom, prosperity and peace form a virtuous circle.

Similarly, Bill Clinton, former US President, on why China should join the WTO in 2000:

> The change this agreement can bring from outside is quite extraordinary. But I think you could make an argument that it will be nothing compared to the changes that this agreement will spark from the inside out in China. By joining the W.T.O., China is not simply agreeing to import more of our products. It is agreeing to import one of democracy’s most cherished values, economic freedom. The more China liberalizes its economy, the more fully it will liberate the potential of its people — their initiative, their imagination, their remarkable spirit of enterprise. And when individuals have the power, not just to dream, but to realize their dreams, they will demand a greater say….

> State-run workplaces also operated the schools where they sent their children, the clinics where they received health care, the stores where they bought food. That system was a big source of the Communist Party’s power. Now people are leaving those firms, and when China joins the W.T.O., they will leave them faster. The Chinese government no longer will be everyone’s employer, landlord, shopkeeper and nanny all rolled into one. It will have fewer instruments, therefore, with which to control people’s lives. And that may lead to very profound change. The genie of freedom will not go back into the bottle. As Justice Earl Warren once said, liberty is the most contagious force in the world.

There it is stated openly as the justification for free trade. Trade will destroy authoritarian state control from within, expose people to freedom, which they will then demand, and that is why free trade with China is in the USA's best interests.

Liberals (by which I mean essentially all mainstream politics in the West today) have, historically, believed this. The economic pattern and means of production define the social and political environment. Opening up to trade meant opening up to new ideas which would necessarily bring liberalism. I used to devoutly believe this myself! Our politicians, I think, actually believed it, possibly wishful thinking.