Alexander joined Conciliation Resources in August 2009 as Head of Accord and Series Editor. Before this he was a research fellow in the international programme at the Institute for Public Policy Research.

He worked as specialist adviser to the House of Lords European Union (EU) Select Committee in its inquiry into the EU Strategy for Africa, before which he was head of the Peace and Security Programme at the United Nations Association-UK. He has also been an associate fellow in the International Security Programme at Chatham House. Alexander completed a PhD in July 2011.