"Abysmal" and a "political disaster": that was how US embassy officials described Gordon Brown, according to US diplomatic cables released by WikiLeaks this week.

The cables paint a sorry picture of Brown's reputation among American officials, who blamed him for Labour's "post-Blair rudderlessness".

This contrasts rather starkly with the revisionist interpretation, which held that while Gordon Brown was widely criticised at home, he was seen as a strong statesman abroad. The WikiLeaks disclosures do some damage to this view.

Brown failed in his efforts to reach a compromise over the Gary McKinnon case. Washington was supposedly so hard-headed on the issue because it was angry at the premature release of the "Lockerbie bomber" Abdelbaset Ali al-Megrahi. Despite the prime minister's persistent attempts, a "Tobin tax" on financial transactions was repeatedly knocked back by US officials.

Brown's defenders, however, could well argue that it was his willingness to go against US wishes that caused the special relationship to cool ever so slightly during his premiership. Compared to the chumminess of Tony Blair and George Bush, or Blair and Bill Clinton, Brown's relationship with his US presidential peers was strained.

In any case, this has not been a good week for Brown. The latest revelations come just a few days after claims that Brown accidentally torpedoed Blair's bid to be EU president after a fierce argument with the French president, Nicolas Sarkozy.

All in all, not the best week for Brown's book launch . . .