Global justice is a theory that claims that the world, for the most part, is unjust. This field raises many important questions. Firstly, we can consider the fact that many different cultures, societies, and nations have different conceptions of what is just and what is unjust. The first question would be whether or not there is an objective ethical/moral standard or do they vary from culture to culture and society to society. Clearly there are certain ethical and moral standards that are the same across most cultures, but what of the ones that are not? Another question that pertains to global justice is the nature of the world's income inequality. The world at large does not have its wealth and resources distributed evenly. Questions arise as to whether the rich are morally obligated to assist the poor or not. On the other hand, is this the natural order of things that some should end up poorer and the situation is therefore no less just. Notice that the discussion surrounding global justice is not one that seeks to find a particular agent who is unjust, but to consider the situation at large and whether justice is prevailing.
Regardless that the definition of global justice is not completely concrete, we can still strive towards it. But, we would want to know what kind of institutions (national or international) best facilitate global justice. Are global institutions such as the UN, WHO, World Bank, etc the best way to attain global justice? Global justice is important because the lack of it is often quoted as a strong reason for global insecurity. Global injustice leads to anger, alienation, and frustration. This in turns lead to violent actions in the form of terrorism, war, or other milder yet important forms of violence. These are the types of questions that this sub-topic in political theory is concerned with.