Law and order, crime and disorder, and London resilience and safety were Barnes's foremost interests on the Assembly, and chaired the enquiry into the London bombings of 7 July 2005 and was responsible for its report. This has led to his taking a national and international role in the fight against terrorism, particularly in addressing the ability of urban authorities to build resistance and response mechanisms to potential atrocities. In 2007 he spoke at conferences in both Dubai and New York City.