I recently read an anthology which has at least two stories which might have the effect of protectionism and isolationism.
ReVisions, an anthology by Julie E. Czerneda and Isaac Szpindel.
The Terminal Solution, by Robin Wayne Bailey, has AIDS spread from Africa in the mid-nineteenth century. According to the author's note after the story, nineteenth century medicine wouldn't have stood a chance against AIDS. Viruses weren't even suggested until 1898.
So you have a depopulation of England and Europe, many places in Asia, somewhat in N. and S. America as people flee the pandemic. So travel gets restricted, foreigners are suspect, local communities have to depend on their own resources, so more manufacturing is done locally.
The Royal Families of Europe don't give up their opium or mistresses, so
by 1914, the people who occupy the thrones are very far down the line of succession. The Queen of England in 1914 is Susannah, who was 21st in line for the throne, and who didn't even exist in OTL.
The others who might have taken the throne in that year were either dead, sick, crazy, too young, etc.
So no Archdukes visit Sarajevo or anyplace else in the Balkans, WW I and II are avoided. There are other, smaller wars, which are quickly ended due to death and desertions among the troops.
People of African descent are blamed for the pandemic, even if they never lived in Africa, and suffer more discrimination in this TL.
But AIDS in this TL isn't necessarily associated with homosexuality, so they aren't oppressed any more than in OTL.
Eventually, people notice that virgins and people who never used needles are free of AIDS. So people use pills and patches for getting their drugs, and virginity gets more respectable for both males and females.
By 2000, medical science has advanced more, there might be something like the UN, but other international bodies include things like the International Biochemical Society and the British Medical Union.
Most public restrooms have a restroom attendant who has the power to arrest and detain persons who don't observe proper hygiene. Which leads to interesting situations when the attendant is black and the arrestee is the governor of Texas, for example.
But it doesn't happen very often. Most people are careful. People are more prone to obsessive-compulsive disorder, a concern with germs, following rules.
The idea of the internet was conceived at about the same time as OTL; it was a way to transmit information without the risk of exposure to germs; this was a response to discussions of the risk of germ warfare.
But then somebody conceived of computer viruses (OTL, the first computer virus was introduced in 1983); and the concept of the internet was put on hold until computer scientists could develop systems to prevent the spread of malicious viruses, spam, spyware and other nasty stuff.
Getting back to the ReVisions anthology...
The other story where protectionism might be more common is "Out of China" by Julie Czerneda, in which a Chinese scholar figures out that the bubonic plague is spread by the fleas of rats; this has interesting repercussions in later centuries. I'd rather not describe it more; read the story.
