Discrimination and race riots.
The answer is: The Law of Land Warfare, Uniform Code of Military Justice, and Code of Conduct.
The answer may vary from country to country but on an international level the United Nations Charter also provides code of conducts on how modern armies should function in times of war.
These are important in order to provide a moral structure to an Army which can become, as evidenced in history, quite ruthless.
The cold war affect Europe by dividing it between communist and Democratic countries, which essentially divided Europe into Western Europe and Eastern Europe. This divide caused tension, political unrest and economic difficulties.
Increase in efficiency of farming and also resulting in fewer and also got large farms.
