A U.S. researcher is urging China to play an enhanced role in discouraging North Korea from spreading nuclear and missile technology.

In a recent contribution to a diplomacy magazine, researcher William Tobey at the Belfer Center for Science and International Affairs at Harvard University said that with the latest rocket launch, North Korea successfully showed its intent to rely on aggressive strategies to obtain concessions.

The researcher called on China to press Pyongyang to stop the North’s spread of nuclear and missile technology, citing the North’s involvement in Syria’s construction of a covert reactor at Al Kibar.