Hillary Clinton has questioned the mental health of Cristina Kirchner and asked US diplomats to investigate whether the Argentinian president is taking medication to help her "calm down". The US secretary of state painted Kirchner as a volatile and emotional leader who suffered from "nerves and anxiety", according to a secret cable sent to the US embassy in Buenos Aires. Clinton asked diplomats a series of questions in December last year which could infuriate Kirchner and sabotage a recent rapprochement between Argentina and America. In a section headed "mental state and health" she asked how the first lady-turned president was...