John Brennan, a former career CIA officer who worked closely with the Bush administration, lambasted the policies of President George W Bush and made the case for a broader approach to fighting Islamic extremism.

Mr Bush's policies, he said in a speech in Washington, had run counter to American values, undermined the security and resulted in a "global war" mindset that served to "validate al-Qaida's twisted world-view".

All this, he insisted, would change under Mr Obama. "Rather than looking at allies and other nations through the narrow prism of terrorism – whether they are with us or against us – the administration is now engaging other countries and peoples across a broader range of areas."

The term "global war on terror", which became so prevalent under Mr Bush that it earned its own acronym – GWOT – would be a thing of the past.