Prof. Myjer is Professor of Conflict and Security Law within the Faculty of Law at Utrecht University. He is co-editor in chief of the Journal of Conflict and Security Law  (www.jcsl.oxfordjournals.org), which he co-founded with Prof. Nigel White of Nottingham University. He is a member of the Committee on the Use of Force of the International Law Association. He has published widely on issues in the area of conflict and security law with special emphasis on arms control law. He is director of the Centre for Conflict and Security Law (www. http://conflictandsecuritylaw.org/). One of the special  focus areas of the Centre is the international law relating to the non-proliferation of nuclear weapons and the law relating to Chemical, Biological, Radiological and Nuclear (CBRN) Security Since the PrepCom, that was established to prepare the entry into force of the Chemical Weapons Convention (in 1997) with its Organization for the Prohibition of Chemical Weapons (OPCW), he has been advisor to the Netherlands Delegation to the OPCW. Eric Myjer furthermore is a judge (locum) with the The Hague Court of Appeal.

He was vice-chair and a member of the Confidentiality Commission of the OPCW, a member of the Advisory Council on International Affairs of  the Netherlands Ministry of Foreign Affairs, and a member of the Committee on Arms Control Law of the International Law Association .

At Amsterdam University he was an associate professor of public international law . He previously worked as a diplomat, focused on issues of arms control law, within the Netherlands Ministry of Foreign Affairs, as a practicing lawyer with Van Doorne Advocaten (previously Van Doorne and Sjollema jointly with Clifford Chance), and (was trained) as a judge. At Leiden University he was attached to the Netherlands Council on Legal Cooperation with Indonesia. He was a research fellow at the Department of War Studies of Kings College (London), for which he was awarded a Ford Foundation Fellowship, and at the Polemological Institute of Groningen University. He took his doctorate  at Groningen University with the renowned public international lawyer Professor B.V.A. Röling.