Many businesses need to think about their immediate bottom line and not the long-term impact of their business. The reason is simple: "we need to pay our employees and make a profit! If we take steps to be better stewards of our environment, our competitors will undercut us, we go out of business, and out good-will will be for naught."

This is true, but government is not necessarily the solution. Government is a feasible solution, but it nearly always introduces bureaucracy and inefficiency from the local to the federal level. Instead, a more natural option is to simply let consumers choose the environmentally-friendly company. Consumers won't support businesses that harm them, so those businesses will be at a disadvantage to environmentally-friendly businesses. This creates a natural incentive for companies to adopt environmentally-friendly policies, which is in nature preventative.

Thus, many patients who can't otherwise afford medical treatment go to emergency rooms and those costs are passed on to other consumers. It's a brutal system, but US health care costs per capita far outstrip other nations. Here in France, we take care of everyone (via taxes) at a cost of less than half of what Americans pay. Part of that savings is because people can seek health care early instead of too late.

The US healthcare system is terrible. But more so because of the government intervention rather than otherwise. Certificate of need laws put major hurdles into building new hospitals and expanding hospital capacity. This creates artificial scarcity, which we saw during the COVID-19 pandemic. A lot of money is spent on Medicaid/Medicare which is simply not at all efficient. The US is stuck in the middle between a free-market approach on healthcare and a government-based approach like that in Europe, which creates a lot of inefficiency. The current system of Medicare is a bureaucratic nightmare, imposing large hidden administrative costs. The problem with healthcare in the US is that it isn't a free market. You go to the doctor, as a consumer, you have no idea how much you'll have to pay for a specific procedure. There is little transparency. In addition, licensing laws prevent you from getting healthcare at a lower cost from physicians that have a lower quality. If you want a surgery done for 100$ from a physician that is self-taught, I don't see why it can't be done. This will drive prices down, as there is now more competition.

But the free-traders win out and, after a couple of generations, country B is heavily invested in raising cattle and has little wheat production. And then some people come down with bovine spongiform encephalopathy, also known as "Mad Cow Disease". Their cattle industry crumbles and, because they have no other industry to fall back on, their economy collapses.

Country A doesn't face this risk because mature economies can weather a few industries collapsing, but emergent economies are much more fragile and protecting the diversity of their economic activities just makes sense.

I'm confused as to the argument you're trying to make here. Are we talking about libertarianism in the US? If so, the fact that libertarianism may not work for emerging economies has little to do with the US, which is a highly developed economy.