Native peoples of America had no immunity to the diseases that European explorers and colonists brought with them. Diseases such as smallpox, influenza, measles, and even chicken pox proved deadly to American Indians. Europeans were used to these diseases, but Indian people had no resistance to them.
US is more rude to Native Americans. While US is more kind to in foreign affairs because they want to get stuff out of the trade.
The answer is, Nations must cooperate to bring about and maintain world peace, and No country must develop or own any sort of nuclear weapons.
They were required to work for the government one month per year.