Nato says it has not been asked to assist a military alliance in Mali. This after Benin President Boni Yayi, who is at present head of the African Union, urged Nato to step in. On a visit to Canada, a Nato-member country, Yayi asked Prime Minister Stephen Harper to contribute troops to the African-led force that is set to intervene. Harper declined, saying Ottawa has no plans for a direct military intervention. Robert Fowler, a former Canadian ambassador who was kidnapped in the Sahel by al-Qaeda in the Islamic Maghreb four years ago, says Canada should play a more active role in Mali. Robert Fowler is the author of A Season in Hell.