The fall of the Western Roman Empire - also called the fall of the Roman Empire or the fall of Rome - was the process of decline in the Western Roman Empire in which the Empire failed to enforce its rule, and its vast territory was divided into several successor polities. The Roman Empire lost the strengths that had allowed it to exercise effective control over its Western provinces; modern historians posit factors including the effectiveness and numbers of the army, the health and numbers of the Roman population, the strength of the economy, the competence of the Emperors, the internal struggles for power, the religious changes of the period, and the efficiency of the civil administration. Increasing pressure from invading barbarians outside Roman culture also contributed greatly to the collapse.

Yet, if we decide to analyze an earlier period in the history of Rome, we will see some of the same characteristics:

The "Crisis of the Third Century", also known as "Military Anarchy" or the "Imperial Crisis" - 235 – 284 AD -, was a period in which the Roman Empire nearly collapsed under the combined pressures of barbarian invasions and migrations into the Roman territory, civil wars, peasant rebellions, political instability - with multiple usurpers competing for power -, Roman reliance on - and growing influence of - barbarian mercenaries known as foederati and commanders nominally working for Rome - but increasingly independent -, plague, debasement of currency, and economic depression.

And still, roman civilization didn't fall during the Crisis of the Third Century.

So, what, or rather speaking, at what point is it possible to establish with certainty the fall of a State, even if the same characteristics could be applied in different scenarios?