...that helps you understand the world, by treating theories as if they're different coloured lenses.

So to use a simple analogy, if you were to wear yellow sunglasses, the world would look yellow...

...if you had red tinted sunglasses, the world would look red and so on.

Well that's how we use theory, that is to say we see the different theories of world politics...

...as ways of understanding the same issue from different perspectives, so in that sense...

...theories are not something separate from the world that report on the world as it really is...

...rather theories are things that construct what we see, so if you take one theoretical position...

...you'll see a certain set of events, if you see it take another theoretical position...

...you'll see a different set of events.

So the book outlines the main theories and gives you a whole series of studies...

...and examples that you can then apply the theories to.

Let's just take one contemporary case study, the war, the civil war in Syria.

The main theory of international relations, realism, treats the Syrian war in a very simple way.

It sees it as a struggle for power, it sees the role of the United Nations as limited...

... it sees the various great powers competing for how they will affect a change in Syria...

...the Russians and the Chinese vetoing anything in the United Nations...

...because they don't want the United Nations to intervene in the sovereign affairs of a state.

ou see the British and the Europeans and the Americans are trying to support the rebels...

...but being restricted in their ability to do that because they don't have the sheer power...

...military and political power, to intervene, it would be difficult.

So realists see the Syrian con- conflict in a quite specific way.

Liberals, the other major theory of world politics, tend to look at Syria...

...as an attempt to construct consensus to see how you can get norms and rules and laws and cooperation...

...to solve a problem.

So they would focus on all those leaders in the world...

...who are trying to bring peace to the region and they would see the role of the United Nations as central...

...and they would point out that over time, the UN and world bodies...

... have a greater opportunity to influence events than they did hundreds of years ago...

...so in that sense, liberals look at the conflict in Syria in a different way.

If you then turn to a theory such as Marxism, Marxists have a very, very different set of glasses...

...to look at the Syrian conflict if you like, than the other two main theories.

Marxists look at this, look at Syria as a conflict really, ultimately determined by oil...

...by centrality in the Middle East, by ruling classes, by economic power...

...and they look at it as a clash of economic interests and they see the Assad regime...

...and the opponents as representing different economic interests globally and their concern...

...really is not so much with the details of the conflict...

... as with the great conflict through history between various competing economic forms.

Those who look at ethics, obviously, look at the conflict in a very different way...

...they're concerned with the ethical issues about when should you intervene...

...is there a, a duty to intervene? Is there a right to protect?

Is there a need to support people who are being killed in other countries?

Or should, ethics people would say, should governments stay out of other people's conflicts?

Then you've got post structural theories and post-colonial theories as well...

... I won't go into them in detail, the point I want to make is all these different theories look at the same conflict...

...but look at it in a different way, what it gives the reader the opportunity to do is to look...

...at the information from different perspectives and therefore we ask the reader...

...to reflect upon the way in which your view about how the world operates colours what you see...

...so we're trying to make a bigger theoretical point in globalization of world politics...

...which there isn't a simple common sense view of the world that's right but instead...

...what we have are different theories that paint a different picture of reality...

...and it's therefore up to the reader to judge which theory is most suitable, which theory is correct...

...which theory they prefer and to know what other theories would say about that issue.

We think that's a unique selling point of the book and all the feedback over the years has been that...

...the ability to give different theoretical views is one of the great strengths of the text.