The purpose of International Relations thoery

Order Description
the essay question :
1. What is the purpose of International Relations theory?
description :
This should be an essay for the MASTERS level . meaning that the conclusion has to be at least worth of 400 words to put togather all what have been discussed in the body . Also both the introduction/ conclusion should provide a clear outline for the argument .
Furher instructions :
avoid being descritive and synthesize exsisting literature and information to back up the argument .
highly analytical /perseuasive argument .
include literature review after the intrudction .
3300 words excluding references .
answer the question directly ( do not change the question ; answer it as it is ).