Foreign Secretary William Hague has called for an end to feelings of "post-colonial guilt" and said the United Kingdom should show renewed confidence on the global stage.
Mr Hague said the country was now seen in a different light from the days of empire, and the difficult economic circumstances underlined the need for a more ambitious approach.
The former Tory leader also played down speculation that he could be moved as part of David Cameron's anticipated reshuffle, stressing his return to frontline politics was based on a desire to concentrate on foreign affairs.
He told London's Evening Standard that new diplomatic missions opened in India, China, Africa and Latin America were "part of the expansion of British presence in the world".
In Africa the older generation will still think of Britain "in colonial terms", he acknowledged. "But that is a small minority of the population there. This is a new and equal partnership," he said. "It's a world where networks defeat hierarchies and where the world is not in blocks. It is the networked world and Britain is a natural centre."
With the UK enjoying the global spotlight as a result of the Olympics and Paralympics, Mr Hague added: "I think we should just relax. It's a long time ago, the retreat from empire."
He said Harold MacMillan's wind of change speech, acknowledging independence movements in Africa, was in 1960 "before I was born".
"It's a different generation. Britain is seen in a different light", he said. "We have to get out of this post-colonial guilt. Be confident in ourselves. The lessons we should take from the admitted need for austerity, saving money, is that we actually need to be more ambitious, not less."
As well as his role in the Foreign Office, Mr Hague is also First Secretary of State and one of the most senior members of the Cabinet.
Reports have suggested he could become Tory party chairman, or even replace George Osborne as Chancellor, in Mr Cameron's first major reshuffle, but Mr Hague said: "I've always been clear I came back into frontline politics to do foreign policy and that's what I'm here doing."