The usual word is traitor.
A person who goes against their own country is often referred to as a "traitor" or a "defector," depending on the circumstances of their actions.
That is a traitor
No, a scab is a dry, rough protective crust that forms over a healing wound on the skin. It is not related to a person returning from a country they emigrated from.
"Corruption of Blood" is when a person is convicted of treason and the federal government punishes the person's innocent family members also. It is against the law and is described in Article 3, Section 3, Clause 2 of the United States Constitution.
The world does not have a capital because it is composed of many different countries, each with its own capital city. The idea of a single world capital would imply a centralized global authority, which goes against the principles of sovereignty and self-governance that are foundational to modern diplomacy.
Something that is undemocratic goes against the principles of democracy, such as limiting the rights and participation of citizens in decision-making processes, suppressing freedom of speech, or concentrating power in the hands of a few individuals or groups.
A corrupt cardinal is a high-ranking official in the Catholic Church who is involved in unethical or illegal activities, such as embezzlement, bribery, or abuse of power. This goes against the principles of integrity and morality expected of clergy members within the Church.
Defector, Traitor, Double Agent.
this person is called a soldier
A person who goes against the flow (of society, their community, their established culture, and so on) might be called a nonconformist.
They are treasonous and are called traitors.
A traitor is a person who betrays someone else or a group/organization. They could also be someone who commits treason against their country.
treason and they're called a trader
rebel is a person who goes against his/her superiors. A rebel soldier would rebel against his/her country's army or organization. MistroJoe
this person is called a pedestrian
Modern.
A holidaymaker or tourist
An astronaut or a cosmonaut.
Such a person could be refered to as precocious.