DW: There seems to be a shift in President Rouhani's approach, in a way that is reminiscent of former President Mahmoud Ahmadinejad's rhetoric about the US. If this is the case, what do you think is the reason behind it?

Sadegh Zibakalam: First of all, I think you are right. Many observers are worried that Rouhani's position is a repetition of former President Ahmadinejad. Rouhani is, more or less, using the same tone and the language. It appears that he is trying to appeal to hardliners and radicals in Iran, rather than getting the support of moderates and reformists.

Rouhani came to power promising negotiation and diplomacy to solve Iran's problems with the West and the US. Does it seem that now he is not going to implement these promises?

Rouhani seems to have let down the 24 million people who voted for him and it appears that he is losing a lot of their support. It also appears he is moving away from moderation and shifting towards radicalism, not only in Iran's domestic politics, but also when it comes to relations with the US and Iran's neighbors.

Over the past year, we have been observing President Rouhani shifting from being a moderate who is close to reformists, to becoming more radical. This is also apparent in Iran's foreign policy.

Rather than trying to negotiate with the US, Rouhani is increasingly using threatening language, which is very dangerous. He does not realize he isn't talking to Barack Obama, but to Donald Trump, who is under pressure domestically and could use an attack on Iran as a potential tool to escape this pressure.

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You mentioned that President Rouhani has decided to get closer to hardliners, rather than reformers or moderates. Do you think this move will impact Iran's negotiations with the EU?

I think it would. I believe that President Rouhani's approach and radical language towards Washington is dangerous. At the same time, he has damaged the rapprochement between Iran and the EU.

As we know, even after President Trump decided to walk away from the nuclear deal with Iran, the Europeans more or less have been rallying behind Tehran and are trying to prevent the complete collapse of the deal. Unfortunately, the approach adopted by Rouhani will strengthen Trump's hand and could push EU leaders towards Trump, rather than towards a neutral position vis-à-vis Iran and the US.

You agreed that Rouhani is repeating the tone that Ahmadinejad used, and on Sunday he was quoted as saying: "War with Iran is the mother of all wars." What do you think about this?

This is a very dangerous course that President Rouhani has adopted. It reminds us not only of Ahmadinejad, but also of Saddam Hussein when he used exactly the same phrase. I wish someone would have told President Rouhani that Obama is no longer in the White House and we are facing Trump.

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Looking at both sides, can we expect a change of tone from Trump, similar to his change of tone towards North Korea?

I think the North Korean leader generally wanted rapprochement with Washington, but I doubt if radicals in Iran want rapprochement with the US. They are not prepared to pay the price for rapprochement. Any rapprochement with the US means that Iran has to withdraw from Syria, possibly from Yemen, and also must reconsider its support for Hezbollah and Hamas. These are the steps that hardliners would definitely not like to take.

It seems that hardliners have the upper hand in Iranian foreign policy. Do you think Rouhani has completely moved away from the reformists' camp and they cannot do anything to change his course?

I think it would be a bit early to reach the conclusion that the game is over and the hardliners have taken complete command of Iran's foreign policy. But we can say that we are definitely moving in that direction.

Sadegh Zibakalam is a professor of political science at Tehran University

This interview was conducted by Jamshid Barzegar, head of DW's Farsi service