Well that would likely hinder the trade for such nation, like China. China has a TON of industry, and what would happen of it couldn't reach outside its borders? The economy would plummet! It would weaken every aspect of the nation.
Most provinces in the middle-east and Spain and the balkans and the low countries region
There are hardly any
It's mostly side effects such as mild fevers and stuff, but vaccines are a must
They were afraid of Germany to get civil rights so the three allies formed a treaty known as the Treaty of Versallies and took away almost everything from Germany and blame Germany for the start of the way and paid tons of money to rebuild everything that was lost.
They had extremely fertile land and lots of manpower, so it made for profitable business.