TPM Reader WB flags this passage in a piece just out from the Times of London ...

But there are deep fissures within the US Administration. Robert Gates, the Defence Secretary, who has previously called for direct talks with Tehran, is said to be totally opposed to military action.

Although he has dispatched a second US aircraft carrier to the Gulf, he is understood to believe that airstrikes would inflame Iranian public opinion and hamper American efforts in Iraq and Afghanistan. One senior adviser to Mr Gates has even stated privately that military action could lead to Congress impeaching Mr Bush.

A bit further down there's this ...

The hawks are led by Dick Cheney, the Vice-President, who is urging Mr Bush to keep the military option “on the table”. He is also pressing the Pentagon to examine specific war plans — including, it is rumoured, covert action.