Power <span>is the ability to manipulate, influence, or control other people or events. Power can be found in someone anywhere, doing anything. When a person posses power they have the ability to control people or tings around them in ways that others without power can not. Power is powerful and can be harmless or harmful to others depending on the situation. </span>
So, the core of the study is the behaviour and personality - and this is usually studied by psychology. Therefore we can guess that we are looking for a branch of psychology.
This branch is social psychology - it focuses how the society (social environment) influences this behaviour.
This is a little open for interpretation, but I would generally say that the best answer is that Josip Broz Tito was a very powerful leader, who kept the republics and the different groups together.
For example, we can see this from the fact that the first conflict happened in 1981: one year after his death ( a protest of Kosovans who demanded autonomy).
Please could you indicate what changes are there discussed by the text
