CARACAS (Reuters) - Venezuelan security forces have arrested an American citizen who entered the nation illegally with geographical coordinates in a notebook, President Hugo Chavez said on Thursday. In the tense run-up to an October 7 presidential election, the socialist leader has frequently mentioned the possibility of violence by opponents with U.S. backing. Foes say that is typical grandstanding nonsense from Chavez, intended to curry support with the masses for his re-election bid by presenting himself as a victim of "imperial" plots. ...