Take a close look at countries where contested votes have led to disaster, from Africa’s Gabon to 2009 Iranian protests

The bitterness unleashed by the Donald Trump-Hillary Clinton election battle has some worrying about what happens if the US election results are challenged. But for all its ugliness, the 2016 campaign in the United States is tame stuff compared with elections in less robust democracies. In many countries, when presidential candidates refuse to accept defeat, chaos…