The tiny Pacific island of Nauru has spent weeks completely cut off from the outside world after its telecommunications network collapsed. Its isolation is so complete that no one is even sure who the country's president is any more. Nauru, an isolated speck in the southwest Pacific with a population of 12,000, is in a "critical situation", according to the last message received by the outside world. That came via an address given three weeks ago by the man last believed to be running the country, President Bernard Dowiyogo, details of which were given on Friday by Radio Australia....