Fragile democracies

The political crisis in Thailand got me thinking about young/fragile/unstable democracies. I haven't spent too much time googling these thoughts so here goes:

Some defintions (or how should we define these terms?):
1. Young - a country that has been democratic but "not for too long of a time".
2. Fragile - a democratic country that shifts back and forth between democracy and autocracy OR a country whose democratic leader is unable to serve out his or her term and has had numerous elections or by-elections to find a new leader.
3. Unstable - a democratic country that has many "events" against the leadership, e.g. strikes, protests, attempted coups.
4. Democratic - any country that holds elections.

Research questions:
1. Are young democracies necessarily fragile/unstable?
2. Are there "old" democracies that are fragile/unstable?
3. Are fragility and instability synonymous?

These concepts don't lend well to quantification or any kind of a cross country analysis which is what I'd like to see. I may have to be content with narratives.

Update: From The Economist, comes charges that the revered king of Thailand ["Father"]constantly intervenes in politics:

Other countries, from Spain to Brazil, have overcome dictatorial pasts to grow into strong democracies whose politics is mostly conducted in parliament, not on the streets. Thailand’s failure to follow suit is partly because “Father” has always been willing to step in and sort things out: his children have never quite had to grow up. The Democrats, the parliamentary opposition, are opportunists, cheering on the PAD while seemingly hoping for another royally approved coup to land the government in their lap.

And I've always wondered if PAD had some implicit royal support since they were never arrested after taking over the airports and they've claimed to be acting in the King's name by carrying his pictures in rallies:

.... The death of one PAD member, apparently blown up in his car by the bomb he was carrying, was quickly buried. But the death of a young woman, reportedly when a police tear-gas canister exploded, became a cause célèbre.

Up to this point there were only whispers as to why the PAD enjoyed such lenient treatment—even from the army, which refused to help the police remove protesters from government offices. However, rumours of an extremely influential backer were confirmed when Queen Sirikit, attended by a clutch of cameramen, presided over the dead woman’s cremation. The king remained silent.

... But the PAD’s ever more menacing behaviour, the palace’s failure to disown it, and the group’s insistence that Thais must choose between loyalty to Mr Thaksin and to the king, may be doing untold damage to the crown itself. Some of Mr Thaksin’s voters must be contemplating the flip-side of the PAD’s argument: if the monarchy is against the leader they keep voting for, maybe it is against them. Such feelings may only be encouraged by the PAD’s condescending arguments that the rural poor, Mr Thaksin’s main support base, are too “uneducated” to have political opinions, so their voting power must be reduced.

And from a commenter (I hope I have the link right):

Thaksin may have been corrupt, although there are a lot more allegations than proofs floating around out there, and media-exaggerated nonsenses - but it's pretty hard to be a top level Thai politician and NOT be corrupt. What I think is that Thaksin was not corrupt enough - he had the insane idea of taking some of Thailand's tax money and spending it on peasants via farm loan writedowns or health care schemes or free public transit, things like that - and that infuriated the older ruling politicians ( who were all (and are) a great deal more corrupt, and openly so, than Thaksin ever thought of being), so, led by this extremely wealthy Sonti who apparently thinks the nation's coffers are his and his cronies personal chequing account, decided Thaksin had to go so the normal order of seriously corrupt politicians milking the nation's treasury could be resumed, and this spending money on the peasants brought to an end. All else followed, and continues following.

Or perhaps he was too corrupt. After his sale of Shin Corp he should have spent more time distributing his wealth among all the other corrupt politicians instead of keeping it all to himself.