Falconer worked in the UK government's
Department for International Development from 2009 to 2013, and then the
Foreign and Commonwealth Office until 2022. His diplomatic career centred on national security and humanitarian relief, including hostage recovery. Whilst in the Foreign Office, he spent a year at
Yale University as a "World Fellow". Since leaving the Foreign, Commonwealth, and Development Office, Falconer worked as an associate fellow at the
IPPR,{{Cite web |date=2023-12-18 |title="National Securonomics": National Securonomics ==Political career==