DW: To what end is the "Islamic State" (IS) filming beheadings and publishing them online?

Peter Busch: Propaganda is generally directed at a number of groups. Firstly, it is aimed at people who already belong to the group, i.e. members of IS or people who believe in their ideology. The now quite large number of videos and photos can also be seen as a demonstration of power. But, at the same time, it can also be seen as a demonstration of weakness, if such messages of "success" are even necessary to keep up the morale.

It is aimed at two other groups as well: possible recruits and the vast number of IS opponents. On the one hand, IS wants to discredit internal opponents, such as al Qaeda. While the two groups follow the same ideology, they have different ideas on politics. On the other hand, the material is also meant to shock Western governments and force them to act. The sheer fact that we are even talking about IS - from their perspective - can be seen as a form of success.

You said that one objective is to get Western governments to act. Does IS really want the West to step in even further militarily than it already has?

One must conclude this. Because that's what these brutal, power-demonstrating videos are aimed at doing. These clips rattle our values to such an extent that theoretically there would have to be a response to them. Terrorism is often about provoking a reaction. And this war against the infidels, the enemy, is, in the end, what IS identifies with.

So IS assumes that it can defeat its enemy?

That is surely the end objective. Al Qaeda envisioned declaring a caliphate at one point. And IS did it. It controls a relatively vast area. And that itself is a very strong message among Islamists.

The time span between the videos seems to be getting shorter. Does that mean they wish to exert ever more pressure?

The scale of information in social media networks has surely reached new levels. Many people are talking about the high quality of the videos that are specifically targeted at the West. But comments about these things show in fact how we see IS and its fighters: namely as people who can barely speak or communicate. IS controls territory and is in contact with various groups in Libya and Egypt. I think that is considerably more important than the group's ability to produce good quality videos.

With regard to the quality of the clips, it is significant that so much emphasis is being placed on the way they are done, and that is distinctly Western. That means they are targeting the attention of an international audience for recruitment.

It's not just execution films that are being released online. What does the IS media strategy stand for?

It means it is a newer generation of fighters who grew up in the world of modern media. They understand the power of propaganda and they use newer forms of media specifically to spread their messages. The Americans say there are up to 90,000 new messages posted by the Islamists on social media networks daily. This number is intimidating to many people. The first question that many governments ask is: "What can be done to stop this?" There are, of course, efforts to wage a counter-propaganda war. But that isn't so easy because in these vast online networks, it is about who exactly is speaking. And what characterizes social networks is their ability to bring people with similar world views closer together.

So does that mean there isn't really any kind of media strategy to counter IS?

It is hard to find a comprehensive strategy. There are obviously any number of anti-IS videos out there that all possible recruits are subjected to as well. And of course, police and secret services can use the social media networks to locate and keep an eye on people with radical views.　

You say followers of IS spread 90,000 messages every day. Is IS striving to become a mass movement?

Naturally, the group is trying to gain as many followers as it possibly can. But what is more worrying for Western societies at this time is the fact that they are using their messages to get certain groups within our societies on its side. It's a kind of subversion, an attempt to break down our societal framework. And that is just as important for IS as finding new recruits; it creates groups that are against the entire religion of Islam and that is a real threat to our political cohesion. It is a threat that should not be underestimated.　

Using this strategy, IS is surely winning battles it doesn't even have to wage on the ground. How does IS propaganda on social media influence the military battles?

That is a good question, but it is a difficult one as well. IS propaganda is, of course, meant to perpetuate the idea that IS has power - not only in Syria and Iraq, but now also in Libya and Sinai. And the message is simply: expansion. There are no limits to the means IS will use to obtain its objectives.

Peter Busch is a senior lecturer in media and war at the Department of War Studies at King's College London.