His distinguished career has featured significant engagement in the major bilateral and multilateral trade negotiations in which Japan has been involved in the past two decades. This includes postings to Japan's diplomatic missions in Geneva and Brussels. He was Deputy Director-General of the Economic Affairs Bureau, Ministry of Foreign Affairs of Japan from 2002-2004 and served as Chief Negotiator for the Japan-Mexico Economic Partnership Agreement (EPA) and the Working Party on Russia's Accession to the WTO. He was Special Assistant to the Minister for Foreign Affairs of Japan in 2004. He has been a member of some task forces such as the one on the Japan-EU EPA as well as on the Japan-India EPA, and more recently on Japan-US Economic Relations under the Minister for Foreign Affairs of Japan in 2016. Prof. Watanabe serves on the Panel on BREXIT issues organized by the KEIDANREN (The Japanese Federation of Economic Organizations). Since April 2015 Prof. Watanabe has been a Statutory Auditor at Mitsubishi Fuso Truck & Bus Company, which is affiliated with Daimler AG.