Ancient greece wasn't a democracy. It was an oligarchy of slave owners.
1) It made use of ostracism - enemies of democracy were excluded from public life (for up to 10 years) in public referendum.
2) It was a direct democracy while modern democracies are representative democracies - which makes them de facto oligarchy of professional political class
3) It balanced citizens rights against duties ie. top tax bracket citizens served in hoplites during the war while lowest class was exempt from military service.
Yes Greek democracy excluded women and slaves but Athenians would be amused by the notion that women could be citizens and modern democracies also exclude non-citizens like low paid, migrant workers from democratic process.
My point - I am attempting to be sarcastic above - is that democracy is a moving target. Athens set certain imperfect model from which we draw upon for the last 2,4 thousand years. And that if you read detailed accounts of Athenian politics surprisingly a lot of their dilemmas could echo today - human nature I guess.
Your examples are good, but my favorite example was the battle of Arginusae, a massive Athenian victory which directly led to the fall of Athens.
In the Peloponnesian War, Spartas army was supreme, but they could never defeat Athens navy. Finally they crushed it at Methymna, and blockaded the remainder, positionihg the Spartan navy to block trade with Athens and starve them.
Athens was forced to build a new fleet manned by inexperienced sailors, and appointed 8 strategoi to lead it against the now vastly superior Spartan navy. Using innovative tactics they won a great victory at Arginusae.
But immediately after, the Athenian commanders were unable to rescue survivors from their disabled/sink ships due to a sudden storm. The citizens of Athens, joyous at the amazing victory, now turned sour. The assembly voted to execute the generals. After they were executed, the war turned against Athens and many realized the mistake they made killing their best generals, so they brought similar charges against the instigators of the charges against the generals.
Pure democracy is a mob at work.
- If democracy is truly power to the people, then the people should have any power, including the power to subvert their own democracy. These democratic channels are currently (in Marcuse's 1960s and now) being blocked by use of mass media and the methods of presentation and prevailing orthodoxies in fields from literature to economics.
- When democratic means are blocked, they may require apparently un-democratic means to open, as a democracy would have to use those blocked routes in order to unblock them, an extra-democratic method is required.