After a campaign lasting several months, the Mexican president, Felipe Calderon, has secured the resignation of the US ambassador to the country, whose criticism of the government's efforts to tackle drug-related violence was revealed by WikiLeaks.
President Calderon called the ambassador, Carlos Pascual, "ignorant" in his criticisms and the relationship between the two men soured further because Mr Pascual had begun dating the daughter of a senior opposition politician.
Mr Pascual had described in cables back to Washington how corruption and inter-agency disputes were hampering the Mexican effort to tackle organised crime, and how a perception that Mr Calderon had failed to bring security to the country has seemingly doomed his party to defeat at the next presidential election.
In a visit to Washington earlier this month, Mr Calderon is believed to have requested the removal of the US ambassador.
In an example of the ongoing diplomatic fall-out from the WikiLeaks revelations, US Secretary of State Hillary Clinton said she and President Barack Obama had accepted Mr Pascual's resignation "with great reluctance".
The countries have a sometimes difficult relationship in their war on drugs.
The Mexican government has been frustrated by the US inability to tackle the smuggling of weapons into Mexico. It emerged this month that the US has started unmanned drone flights over northern Mexico to track the movements of the drug gangs.