Wyn Rees is a professor in the school of politics and international relations at the University of Nottingham. He specializes in international security issues and also serves as a visiting professor at the College of Europe in Bruges.

Deutsche Welle: The storming of the British Embassy in Tehran has put more pressure on the already strained diplomatic ties between Britain and Iran. Prime Minister Cameron has warned of "serious consequences." What do you expect the British response to entail other than to pull out its staff out of Iran which it has already done?

Wyn Rees: I think the severing of diplomatic relations has been the key response to the storming of the embassy. I think the British have been very indignant about the fact that this obviously had a degree of complicity by the Iranian government. The protestors that actually stormed both the British embassy and the compound where embassy staff live clearly were doing so with the tacit agreement of the regime. So in that sense the British have reacted quite strongly by pulling out and now asking the Iranian embassy in the UK to actually leave by the end of this week. I think in that sense the kind of diplomatic side is now at an end and I don't think much more is going to happen in that regard.

How does the British public view this conflict? Could this create greater support for a tough stance by the British government against Tehran?

I think so. The British public have long been critical of the way in which Iran conducts itself. We saw the disputed election in Iran in 2009 and the crackdown of opposition groups in Iran, so I think this came against the back lot of traditional kind of tension between the UK and Iran. And clearly the nuclear issue kind of overshadows that and is the core of the tensions between the two countries at the present time.

What is the sense in Britain why the British embassy was attacked? After all Canada also instituted tougher sanctions against Iran and France has also taken a tough stance. Does it have anything to do with the fact that Britain has had repeated tensions with Iran in past decades?

I would make three points. One is that there is a deep background tension between the UK and Iran which goes back many decades and the Salman Rushdie affair and various other background issues which have been there for a long period of time. Secondly, the UK, France and Germany, the so called E3, the European Union three countries, have been taking the lead trying to stop Iran from developing nuclear weapons. Thirdly, I think the spark that set this particular episode off was the fact that the UK went further in financial and banking sanctions against the Iranian regime which is frankly going to do a fair degree of damage to the Iranian economy and the ability of Iran to do business around the world and acquire funds to conduct its activities. That's going to be seen as really quite damaging to the Iranian economy in the longer term.

You mentioned the nuclear issue that is always looming in the background. What are the implications for the nuclear issue from this new fallout and the tougher stance by the international community on Iran?

I think that's the really scary one for the future really: The fact that there has been a long process of ratcheting up by European governments and the United States against the alleged Iranian nuclear weapons program. We saw the recent IAEA report kind of confirming that the UN regards Iran actually to be building nuclear weapons and we are now seeing the move toward really tough measures against Iran. The United States is at the forefront of that. Clearly Israel has a very strong interest in this as well. In addition there is real tension now in the international community about how to stop Iran from taking the final step from the kinds of technologies it needs to produce nuclear weapons to actually weaponizing and producing its first actual devices.

How will this play out over the next few months?

I think this is going to keep ratcheting up. William Hague, the UK foreign secretary, is in Brussels trying to get tougher EU wide sanctions against Iran. And that goes very much toward the nuclear program. I think the diplomatic issue has stopped with the expulsions of embassies, but now it's about putting tighter pressure on the Iranian regime. There are already travel bans on leading people in the regime, assets have been frozen. They are now talking about an oil embargo against Iran and that would do a lot of damage to Iran which depends very heavily on its sale of petroleum overseas. So I think we are in for a period of high tension between European governments, of which Britain, France and Germany will play a leading part, and Iran.

In light of the new IAEA report there's also been renewed talk about possible military action against Iran's nuclear facilities. What is the mood in Britain about such a step?

I think there's an acceptance in the UK that those kinds of decisions are going to be made in either Tel Aviv or Washington really, because those are the leading actors when it comes to a military response. If it were to come to that - God forbid - then I think there are other countries like Britain that would be party to those discussions and may even participate if it were to come to some sort of targeted military action. But hopefully we can see economic sanctions and continued economic pressure being exerted on the regime sufficient to actually get it to stop its program and to back down. But I think the military threat is always looming in the background.

Interview: Michael Knigge
Editor: Rob Mudge