The leader of the Islamist extremist group Boko Haram Abubakar Shekau (C) delivering a speech. Boko Haram has grown from a small terror group to a mini-country with its own territory, which can be compared to gains made by the Islamic State (IS). Boko Haram now controls an area the size of Costa Rica or Slovakia. The militant group’s territory now totals about 52,000 square kilometers, according...