Gender can affect people's life chances in various ways - for example, if you're a woman you are paid less for doing the same job as a man, this is called the gender pay gap, which is a huge uprising issue of our modern world. Also, in some Asian and Middle Eastern countries women are given less rights than men e.g. education struggle - just because they're women. This gives women less chances to be independent in their life in the way that men easily can be.
The Americans felt that it was their destiny to expand their territory. They didn't want any other countries to take land from them. They only wanted to protect their land.
They were justified.
There are some barriers to this concept that speaks about the reality that if a person accepts global citizenship, then he/she will not be considered fully as part of one nation and that one has to face difficulty in living in the social standards of the nation.