How were the reasons for empire growth and decline similar and different in various world regions?

From the collapse of ancient Rome to the fall of the Mayan empire, evidence from archaeology suggests that five factors have almost invariably been involved in the loss of civilizations: uncontrollable population movements; new epidemic diseases; failing states leading to increased warfare; collapse of trade routes

basic principles: federalism, separation of powers, checks and balances, judicial review, representative democracy, limited government, rule of law, individual rights and responsibilities, consent of the governed, majority rule, popular sovereignty, equal protection.