I’m guessing a sewage system
Realpolitik.
.
It's a theory where politics are based on practical matters rather than theory/ethics.
The are most of the time open ports, which leaves room for imports and exports.
I am assuming you are asking for major powers:
Axis:
Germany
USSR (First period)
Vichy France (Later half)
Japan
Bulgaria
Allies:
United States
Canada
France (Later Free France)
USSR (Latter part)
China
United Kingdom
Answer:
It may damage our life
Explanation:
We will suffer from many harmful disease
