Sanctions against Russia for its involvement in Ukraine "must be tightened," demanded Cem Özdemir during a 30-minute interview that was dominated by foreign policy issues. The situation in Eastern Ukraine is deteriorating: "Therefore I see no reason to lift sanctions."

DW editor-in-chief Ines Pohl and reporter Jaafar Abdul Karim quickly moved on to another topic that has a lot to do with Özdemir, who has often described himself as an "Anatolian Swabian." His parents immigrated to Germany from Turkey.

When asked about the current row between Germany and Turkey over the right of German parliamentarians to visit troops stationed at NATO's Konya airbase in Turkey, Özdemir said that Turkish President Recep Tayyip Erdogan was "not acting in accordance with NATO rules, and more like a thug in a bar."

He went on to demand that NATO headquarters in Brussels give a clear statement on the issue. He says the dispute is not one between German Chancellor Angela Merkel and President Erdogan, but rather between NATO and Turkey.

And how would Özdemir proceed with Turkey's EU accession talks? "I would leave them where they are now, in the back aisle of the refrigerated section." He said if Turkey were to introduce the death penalty: "Then talks would be over for good. And Turkey would have to leave the Council of Europe."

'Germany is a bit too naive'

Abdul Karim, who often deals with sensitive topics in his Arab-language DW show "Shabab Talk," then asked Özdemir what must be done to improve immigration and what the Green party would do differently if it were in a governing coalition.

Özdemir responded by declaring that any attempt to create a "parallel society in Germany" must be stopped immediately. He said that too many Turkish opposition supporters have come to him fearing they are insufficiently protected in Germany. "I feel we need to give a crystal clear answer that we will not tolerate anything like that here. I think Germany is a little too naive in that regard."

In that same context, he also criticized Chancellor Angela Merkel for being too "soft."  He claimed that "integration-minded people" on the executive boards of mosques are being removed "and replaced with people that are getting their orders from Ankara." Özdemir said that was unacceptable: "Erdogan wants to exercise power inside Germany."

Alluding to the increased influence he says Erdogan is seeking, the Green party leader insisted: "In the future there will be no more money from Turkey for mosques here."

Özdemir said that there are simply states – like Turkey, or even Russia under Vladimir Putin – that "clearly do not want their citizens here to integrate."

Özdemir sees investment policy as another way to exert policy pressure on Erdogan. The Turkish president is constantly asking for money from abroad, but German companies must be made cognizant of the fact that Turkey is "no place for secure investment, because there is no rule of law there."

'Merkel's misguided policy on Turkey'

Looking back, Özdemir is quite critical of Germany's overall policy toward Turkey since Chancellor Merkel took power in 2005. The previous Social Democrat (SPD) and Green party coalition government supported reformers in Turkey. When Merkel later pushed the idea of privileged partner status for Turkey in its EU accession talks, she contributed to the demise of those reformers, he believes.

Then, with the refugee crisis from 2015 onward, it seemed as if the chancellor was paying Erdogan a visit every second day in order to complete the EU-Turkey refugee deal. That gave Erdogan the feeling that he was an important international politician. Özdemir summarizes Merkel's misguided policies as having punished the wrong people at the wrong time and rewarded the wrong people for the wrong thing.

'World champions in climate protection'

The Greens could well join Chancellor Merkel – and most likely the liberal Free Democrats (FDP) – in a coalition government after the September 24 election. What could the Greens bring to such a coalition? "Unfortunately, Germany is not world champion when it comes to climate protection," said Özdemir in criticizing the Merkel administration.

Merkel may be presented as a world champion in the headlines, and granted, when compared to Donald Trump she is certainly a "shining light," but as soon as one scratches the surface, it becomes clear that most of her policies are anything but world class. Özdemir emphasizes that "Germany could do a lot better." One has to make clear that there should not be an "or" between ecology and economy, but rather an "and," he believes.

'I'll remember that until the day I die'

Now 51 years old, Özdemir was among the first immigrant children to attend German grade schools in the 1970s. He says that just like the children of Portuguese immigrants, he had to sit at the very back of the classroom.

When he was in fourth grade, he raised his hand when the teacher asked who in the class was planning to go to a "Gymnasium," the top stream of schools in Germany's high school system. He says he'll still remember the class' reaction to him doing this on his deathbed. His teacher and his schoolmates were tied up in fits of laughter over the idea that someone like him would aspire to this.

But Özdemir overcame that bitter experience. He says it spurred his ambition, especially in situations where others thought he couldn't do something: for instance in 1994, when he became Germany's first parliamentarian with immigrant roots, and took up his seat in the Bundestag for the Greens.

Nevertheless, the trained childcare worker never did complete his high school diploma. He says that when others took entertaining novels to the beach for summer vacation, he packed books like Goethe's "Faust" to fill in gaps in his education. Might the trained bookseller Martin Schulz be of some help on that score? In any case, the SPD leader was the politician that Özdemir chose to share a deserted island with – a question posed to all of the candidates in this year's summer interview series. He says that Schulz could talk to him about interesting books.

Next week we will find out if Martin Schulz would choose to take Cem Özdemir with him. The SPD's top candidate will be our next DW interview guest.