It's the sovereign right of any country to be protectionist. Protectionism is actually the default. Open markets is not the default. I'd like to think the open US market is what makes it great, and too much protectionism actually stifles innovation and the robustness of the domestic economy.
The US market hasn't historically been that open. We started this country with tariffs as the only thing funding the government. All the free trade market stuff we have today was carefully negotiated via the WTO, and even then there is a huge bias in supporting allies (remember, when China opened up in the late 90s, it was antagonistic with Russia and actually a US ally since the the late 70s, that is all history now).
