NIAMEY (Reuters) - French Defense Minister Jean-Yves Le Drian said on Friday world powers must tackle instability in Libya but he stopped short of openly backing the military intervention called for by regional powers in the Sahel. Speaking shortly after meeting Le Drian in Niamey, Niger's president, Mahamadou Issoufou, reiterated calls for an international military intervention in Libya, a position supported by several other African leaders concerned about the impact of the country's lawlessness on the region. ...