Can the United States' new strategy on Afghanistan work and what are the implications? President Donald Trump announced last week that he would no longer withdraw troops on the ground, counter to promises made repeatedly on the campaign trail last year. The New Zealand Defence Force has been involved in Afghanistan since 2001, and last week the government announced it will send reinforcements. Kathryn talks with David Kilcullen, one of the world's most influential experts on counterinsurgency and military strategy. He is a former Australian Army Officer, who has held high ranking roles in US government, including as special advisor for counterinsurgency to U S Secretary of State Condoleezza Rice. He's the author of three books, the latest is Blood Year: Islamic State and the Failures of the War on Terror.