Historically speaking, China back in the 15th century or so, was much like the US is now. They were in many ways more advanced than the rest of the world. Then China cut itself off from the rest of the world instituting an isolationist policy.
https://en.wikipedia.org/wiki/Isolationism
I think many still believe that China is yet still recovering from that 15th century isolation.
Some might think that it is a great policy because it prevents those with opposing viewpoints from entering the country, and in this day and age, that is perceived as preventing entry of terrorists to a country. However, it works both ways. Isolationism could prevent exports, and it could prevent imports of technology and ideas that might spur further innovation and economic development.
As I see it, isolationism is a knee-jerk reaction that fosters a feel-good mentality, we're better than they are, we don't need them, and for sure, we will prevent all bad from affecting us. IMO, humanity, though, is at its best when there is a free and open exchange of ideas. Unless there is drastic economic change, and what that might be I do not know, there will inevitably be those who have not wanting to have the things of "those who have," and perhaps, willing to do anything to achieve those ends.
With isolationism, we might pay a heavy price that stands a chance of lasting for centuries. There's a saying about history repeating itself if the lessons are not learned.