A feather and a steel ball are dropped simultaneously from a tall building. Which will reach terminal velocity first?

Reasons militaries intervene: political instability, economic crisis, corruption, ethnic conflict, weak institutions, military ambition. Intervention usually claims to be temporary correction of civilian failure.

Effects: suspension of constitution, rule by decree, human rights violations, corruption (often worse than civilian), delayed development of democratic institutions, uncertainty for business.

Prevention: strong democratic institutions, professional military, civilian control of military, economic development, national unity. Nigerias 1999 transition aimed to end military intervention permanently.