DW: The treaty on the Final Settlement with Respect to Germany, also called the 2+4 treaty, has been called a masterpiece of diplomacy and has been included into UNESCO's Memory of the World. Are those designations justified?

John Harper: I think they are. To start with the second designation, the signing of the treaty on September 12, 1990, can be seen as the end of the Cold War, which was a major episode in world history, not only the 20th century. Although there are other days that one could choose for example October 3, Germany's official unification day.

It was a diplomatic masterpiece for several people, starting with Helmut Kohl, who was really the man who took the initiative to accelerate the process of German unification after the fall of the Berlin Wall and gained the support of the United States and the reluctant support of his European allies. But, of course, one cannot forget Mikhail Gorbachev, who really made it happen by allowing it - to the great surprise of many and to the dismay of many people in the Soviet Union. He first gave the green light to German reunification and a bit later to the inclusion of the new Germany in the Atlantic alliance within NATO, which was the last real obstacle before reunification. So certainly it was a diplomatic masterpiece.

Twenty-five years later, Germany - now reunified - is making global headlines for its willingness to accept large numbers of Syrian refugees.

It can also be seen in a way as a kind of political - if not diplomatic - masterpiece. First of all the way in which West Germany was able to - at great expense and with many, many problems - absorb and finance the unification of the country and take on the GDR. It must be seen as a great historic achievement. Germany has received a lot of criticism for its insistence on austerity and its rather narrow-minded provincial view of the way that the European monetary union should work. I think some of those criticisms are justified. But I think the position of Angela Merkel on the refugee crisis is very much in the spirit of the way in which West Germany opened its doors and its financial coffers to try to reintegrate the former East. There is an interesting parallel there.

Many of Germany's allies, foremost the United States, have repeatedly pressed Berlin to play a bigger role in international affairs. In light of Germany's role vis-à-vis Greece, the Ukraine conflict and the Syrian refugee crisis are these demands coming into fruition now?

I still think Germany is still very reluctant - for obvious historical reasons. And I don't think the German public is eager to play a high-profile role and is quite comfortable with the present situation. So I think the answer is no, Germany has not said yes to these demands. But I think inevitably Germany will have to do that because there is a kind of vacuum of leadership. The United States cannot be expected to play a leading role, for example, on the Ukraine. It has too many other concerns. So Germany will have to. I think on the Syrian refugee crisis, what Germany is doing can only be applauded.

I think Angela Merkel's instincts would be to be more generous and flexible on austerity towards Greece like she has been generous and flexible on the refugee crisis, but it's the German public that, to me, seems to be the obstacle. That is really the big unknown: whether Germany's insistence on austerity is going to be compatible with the survival of the European monetary union. That's very much an open question.

John L. Harper is professor of American Foreign Policy at Johns Hopkins University School of Advanced International Studies in Bologna, Italy.