The "special relationship" between Britain and the United States is over, Nick Clegg has said.
The Liberal Democrat leader said Barack Obama's administration "understood the world had changed" and the UK's leaders needed to end their "slavish" devotion to Washington.
Mr Clegg also warned against "sabre-rattling" over Iran's nuclear ambitions and repeated his pledge to offer a referendum on the UK's continued membership of the European Union when the issue next arose.
The Lib Dems have ruled out replacing Trident with a like-for-like system and Mr Clegg said the UK should consider "not having a continuous at sea deterrent".
In a speech to the Foreign Press Association in London, Mr Clegg said it was time to challenge the "conventional wisdom" that had lasted since the Suez crisis about the UK's relationship with the US.
He said: "I think it's sometimes rather embarrassing the way Conservative and Labour politicians talk in this kind of slavish way about the special relationship. If you speak to hard-nosed folk in Washington they think 'it's a good relationship but it's not the special relationship'."
