I could not agree more with your summary of the 20th Century's leadership failures Mr Hamilton. It's all a damning indictment of the supposedly 'democratic' systems introduced with such high hopes across the Western World in the 1920/30's. Sadly this inability of the masses to govern themselves and also their naive vunerability to exploitation by the unscrupulous and/or criminally inclined was recognised by great philosophers such as Plato long ago.
In his treatise on political governance The Republic (Penguin Classics) Plato explains that Democracy is the third in a cycle of four major govermental systems:- Kingship, Oligarchy, Democracy and Anarchy; with democracy only becoming popular when a previously stable/effective Oligarchic system becomes discredited, as happened in the West due to the catastrophe of WWI. Once established, democracies tend toward unstable divisive government; as the various parties compete increasingly viciously amongst themselves in order to gain even short-term control; whils't evermore seriously damaging the state/nation they misgovern. Within a century or so this deepening factionalism degenerates into anarchy as the rival interest groups turn to force rather than evermore pointless 'elections' in order to gain any meaningfull power over an evermore discontented 'electorate'. The period of anarchy is almost always short but violent, with one faction chief (Augustus, Charlmagne, Napoleon, Hitler, Mao?) successfully erradicating his rivals and seizing total power 'Kingship', which in turn begins a shortlived 'Golden Age' as the new King/Leader attempts to both unite his people and strengthen the power of his realm. Following the death of the 'Great Man' his successors tend toward the establishment of a new oligarchy (rule of the few/elite); thus completing the circle.
Looking at the 20th Century West from this perspective, we see the deeply entrenched factionalism, the declining living standards, rising lawlessness and increasing political incompetence/corruption, just as Plato predicted. If the West follows historical precedent the near future will be a short period of violent anarchy (Already being predicted in films such as:- Mad Max  [DVD] Judge Dredd [DVD]  and the like) followed by a seizure of power similar to that which Putin has engineered in Russia following the bankrupcy/collapse of the Soviet Union.
I assume the alarmingly dismal tone of this philosophy/history based 'prediction' is the reason modern schools no longer teach Classical History? I also sincerely hope Plato's wisdom will prove to be wrong this time round, but I wouldn't bet on it.