The email is only a few sentences long, but it was sent from the most unlikely location: North Korea's capital, Pyongyang. The message came from Im Song Jin, a physicist, and expert in laser optics, in response to a DW request. Im is one of a privileged few to have an email address and be permitted to communicate with the outside world is a sign that he is trusted by the North Korean regime.

Im confirmed to DW that between 2008 and 2010 he was a visiting scientist at the Max Born Institute for Nonlinear Optics and Short Pulse Spectroscopy (MBI) in Berlin. And after that? "I have a business e-mail address in Kim Il Sung University," Im wrote. "By using this e-mail address we communicated and continued collaboration works."

His last joint publication with an MBI colleague appeared in an established specialist magazine in the summer of 2020. This was nearly four years after United Nation member states were called upon to cease all scientific exchanges with North Korea. The UN Security Council wants to prevent North Korea from gaining access to sensitive knowledge and applying it to the production of even more advanced weapons of mass destruction (WMD).

Domestic intelligence agency warned in vain

Germany is one of the United Nations' biggest supporters. So why was the renowned MBI, which is publicly funded, still working with North Korea?

The cooperation continued, even though in 2016 the Federal Office for the Protection of the Constitution, Germany's domestic intelligence service, explicitly warned that despite the sanctions, "ongoing North Korean efforts to procure Western technology can be observed, including in Germany."

A DW investigation of the case has revealed a potential German violation of UN sanctions that could have been avoided. The case throws a spotlight on the potential for conflict between Germany's approach to freedom of research and security concerns.

A series of missile tests

Hardly a day goes by without headlines featuring North Korea. Although most of the East Asian country's population is impoverished, it has never fired as many ballistic missiles as it has in 2022. For weeks now, there has also been mounting concern that it might be about to test another nuclear bomb. It has already conducted six such tests: the first in 2006, and the most recent in 2017.

This is a calculated move by the isolated country: demonstrating strength through weapons technology. Its government sees military development as crucial for regime survival. For that, it needs relevant research and technology.

Since 2006, the United Nations has adopted a total of nine sanctions packages — including heavy restrictions on technology transfer and academic exchange. In 2016, following the fifth nuclear test, the UN Security Council finally resolved that all member states should suspend their scientific collaborations with North Korean researchers.

UN call to suspend research cooperation

This decision, recorded in Resolution 2321, applies across all fields and disciplines. It covers both basic, theoretical and applied research. Exceptions can only be made within the medical sector, or after assessment on a case-by-case basis. This is intended to prevent the transfer of dual-use knowledge that could be used for both civilian and military purposes.

"The possible military applicability of advanced research is notoriously difficult to substantiate, and extremely simple to deny or conceal," a UN insider told DW. Because of the sensitive subject matter, the person does not want to be named.

The source described the threat of this kind of knowledge transfer as "dangerously real" — and added that the UN sanctions also cover remote scientific collaboration via email and joint authorship: "The concern is that such collaboration could serve to advance the intangible transfer of technology of value to DPRK's weapons programs."

China and Germany leading research collaborators

North Korea's extremely rapid military development since the first nuclear test in 2006 cannot be comprehended without technological progress — which is difficult to achieve without knowledge transfer from outside the country.

This is also substantiated by a study by the James Martin Center for Nonproliferation Studies in the United States, which has examined North Korea's international research collaborations from 1958 to 2018.

Among the almost 1,150 studies scrutinized, the leading collaborator, by a wide margin, was North Korea's protecting power China, with more than 900 joint publications. It was followed at a considerable distance by Germany, with 139 publications.

Over the past decade, one German name, in particular, stands out: the MBI researcher Joachim Herrmann. He was involved in several research collaborations that the authors of the American study regard as dual-use risks.

The MBI is a non-profit research institution. It receives half its funding from the Federal Ministry of Education and Research (BMBF) and half in subsidies from the German federal states. In response to an enquiry from DW, the MBI directorate wrote: "The MBI does not conduct any military research, only basic civil research into and using lasers."

Physicist Herrmann has been researching at the institute since its foundation in 1992, continuing even after his retirement. DW contacted him by phone, but he declined to speak on the record.

Two North Koreans in Berlin

Herrmann and the physicist Im Song Jin met in Berlin in late 2008 when the North Korean came on a German Academic Exchange Service scholarship.

A few months later, a second North Korean, Kim Kwang Hyon, arrived at the MBI on a scholarship from the Daimler-Benz Foundation. Kim stayed until 2012 and completed his doctorate.

When Im returned home in 2010, he maintained personal contact with Herrmann. Im had made a good impression at the MBI and was thought of as a particularly fine mind. The two scientists continued to work remotely by email.

Between 2017 and 2020, there were a total of nine MBI publications by Herrmann in collaboration with North Korean scientists. Im worked on eight of them, while the former Ph.D. student Kim worked on the ninth. New North Korean names also appear as co-authors: Im had brought his students on board.

All the joint articles are in the public domain. All deal with basic research in the field of laser technology, which is not geared toward a specific practical goal. However, this does not preclude further development, including military use, at a later date.

Expert verdict on dual-use risk is mixed

DW separately asked 10 independent physicists and disarmament experts to assess the most recent publication between Herrmann and Im.

Among the six physicists, opinions differed. Three judged the study to be innocuous, while three believed it had the potential for military application in the future.

All four disarmament experts interviewed expressed alarm — especially Katsuhisa Furukawa. From 2011 to 2016, the Japanese analyst was a member of the UN panel of experts that monitors sanctions on North Korea.

His conclusion was that while the individual paper may be unproblematic, cooperation as a whole is not. "I am deeply concerned that it has contributed to North Korea's understanding and advancement of various scientific disciplines that could eventually have contributed to the country's WMD program," he told DW.

Furukawa believes that Herrmann's cooperation with the North Korean researchers "very likely constitutes violations by Germany of the UN sanction measures." The former UN official recommended an investigation.

"At a minimum, I think the German government and the Max Born Institute were too poor in the implementation of the UN sanctions, or perhaps deliberately ignorant of the UN sanctions."

Germany relies on individual responsibility

In Germany, freedom of research is protected by the constitution. Scientists are free to choose their partners and projects — there is no political interference. However, this freedom also entails responsibility.

Researchers have a duty to identify possible dual-use risks themselves. If they have any doubts as to whether partners could also use their research for military purposes, they must contact the Federal Office for Economic Affairs and Export Control (BAFA), which oversees this. The BAFA then checks whether or not joint research can be permitted. The impetus, however, must come from the scientific community itself.

When UN sanctions are involved, as with North Korea, things become extremely complicated. The sanctions are only effective if the governments of UN members implement them in a legally binding way in their respective countries. In the case of Germany, this involves both national and European Union legislation.

In the EU, basic research of the kind carried out by the Max Born Institute is not usually subject to official approval. However, the boundary between basic and applied research is often fluid. Exemption from a review of dual-use risks is therefore not automatic, especially when sanctions are involved.

DW asked the federal office about this. It confirmed: "The BAFA examines each individual case to determine whether there is an authorization requirement in this specific instance, and it is happy to assist with delimitation queries." It added that the assessment would also take the human rights situation in the partner country into account.

However, the Max Born Institute did not contact the BAFA. Consequently, no examination of the case was ever carried out.

MBI sees it as the government's responsibility

Herrmann's last MBI publication with North Korean scientists appeared in 2020, almost four years after the strengthening of UN sanctions in November 2016. In its written statement to DW, the MBI said it had ended this scientific contact "of its own accord," because of "growing concern on the directorate about North Korea's role in international politics."

Why did this step take so long? The MBI's position is that the fault mainly lies with the German government. It said the UN resolution to end all scientific cooperation "has not discernibly been implemented in Germany. For example, at no point did we receive a request from the BMBF to suspend scientific contacts with North Korea."

Obligations to request and to supply

Kai Gehring, a Green member of the German Bundestag and chair of its Committee on Education and Research, does not accept this argument. "There are obligations on both sides," he told DW.

"If anyone working in the scientific field has not realized that there is a comprehensive regime of sanctions against North Korea, I would really want to ask them a number of questions about how such a thing can happen."

Scientific exchange can be an important channel of communication with authoritarian regimes, in order to promote liberal values and solve global problems like the climate crisis. However, Kai Gehring stressed that with North Korea the red line of scientific diplomacy was crossed long ago. "North Korea is completely authoritarian, and one of the biggest threats to international security."

Part of the system

The physicists Im and Kim, Herrmann's research partners, are part of North Korea's totalitarian system — whether they like it or not.

Im now teaches at Kim Il Sung University, Kim Kwang Hyon at the State Academy of Sciences. These two elite institutions are essential to North Korea's nuclear and ballistic weapons programs. Furukawa, the former United Nations official, confirmed that the UN has already investigated both institutions over "multiple violations of UN sanctions."

Since his return to North Korea, Im has also published two research papers, most recently in the summer of 2022, with colleagues from the Chinese Academy of Engineering Physics (CAEP). The CAEP also does basic research, but it is principally known for conducting research into, developing, and testing China's nuclear weapons.

Kim, meanwhile, has described North Korea's fourth nuclear test in January 2016 as a "landmark event," telling the state-run Pyongyang Times: "I am determined to push ahead with the scientific research to carry out the tasks set forth by the Supreme Leader […] with the same thinking and in the same working manner as those defense scientists did."

The limits of research freedom

The conclusion, in this case, is a painful one: It highlights gaps in Germany's ability to flag projects at research institutions that could violate international agreements. Despite the high-profile UN sanctions, no one questioned the MBI researcher's cooperation with North Korea. Scientific self-regulation failed to identify a possible dual-use case, and communication by all parties was inadequate, even though the MBI as an institution is funded by the state.

If it is possible for failures like these to take place over a longer period of time, even with a case as flagrant as North Korea, it is clear that the system is vulnerable to exploitation.

"There has to be a much closer collaboration between the scientific community and national security authorities," sanctions expert Furukawa suggested.

Lawmakers are still reluctant to draw clear red lines. The question is a thorny one: In a system where scientists themselves are responsible for flagging suspected dual-use cases, where does freedom of research end? This is especially difficult when it comes to autocratic countries like North Korea, China, and Russia.

All German research collaborations with Russia are currently on hold because of its war of aggression against Ukraine. There is a heated debate about scientific cooperation with China. In the field of research, Germany has not yet worked out how to balance freedom-based values and state security interests.

Additional reporting by Christian Caurla and Julia Bayer.

The story was translated from German by Charlotte Collins.

Edited by: Ruairi Casey and Sandra Petersmann