HARDtalk - Kurt Volker, former US Ambassador to Nato

A draft of Nato's new strategic concept, backed strongly by America, has warned against cuts in defence budgets. But how will cash-strapped members, struggling to manage huge deficits, afford their committments? The United Kingdom is a large contributor of resources to the alliance but within its new coalition government there is potential for division over defence spending and the UK's relationship with the United States. Stephen Sackur asks former US Ambassador to Nato Kurt Volker if historical sentiment should rule over economic reality.