On 21 July 2008, The Secretary General of the United Nations, Ban Ki-moon, appointed Fowler to be his Special Envoy to Niger, with the rank of Under-Secretary-General in the Secretariat of the UN.
While acquitting his UN mission, Mr. Fowler and his colleague, Louis Guay, were captured by al Qaeda in the Islamic Maghreb (AQIM) on 14 December 2008, and held hostage in the Sahara Desert for 130 days.