OK, so a couple of outside websites have stirred the murky pool of neoreaction — a welcome development, I think.
Because of the angle they came at it from (via Mike Annissimov, via Scott Alexander), they rather overstated the importance of monarchism to neoreaction. Monarchy is important as a point of comparison, but it is only one possible approach among several for a neoreactionary future.
Having said that, Anomaly UK is where future monarchy gets seriously proposed, so I’ve pulled together what I think are the main failure modes of monarchy, to put the dangers in the proper perspective. Most of them have been discussed here before, so this is largely an exercise in consolidation and better explanation.
By “failure”, I mean either that the system collapses and is replaced with something else, or that the system survives but is very unpleasant to live under.
There are some failure modes that are common to all systems of government: any system can be invaded by foreigners, or be overthrown by a demagogue. Monarchy, because its distinctive feature is the lack of selection applied to its rulers, and the lack of regular mechanisms for replacing them, has, or is perceived to have, its own peculiar failure modes. Here they are:
Evil Psychopath — I can't think of any. Democracy (particularly one-party democracy) seems to have a far stronger track record of putting evil psychopaths in power than monarchy does.
Liberals — this has historically been the major failure mode. The solution is to permanently discredit democracy and liberalism. The Roman Republic managed to achieve that for Europe for over a thousand years, so I’m optimistic on this point.
Uninterested — this was a major concern throughout the monarchical period, but I struggle to think of examples, at least from English history. Edward II maybe? That’s a long way back.
Sick or insane — this has been troublesome. Modern medicine greatly reduces the risk: the best-known examples have been the result of syphilis or other treatable conditions. Senility is a major worry for a modern monarchy, though.
Child — again, historically a big worry, but not common: it hasn’t happened in England since Edward VI. Better health makes it less likely. The British royal family currently has three generations of mature adults available.
Unclear succession — again, better health makes shortage of heirs a very minor concern. Disputed legitimacy might become an issue: even with the availability of genetic testing, there is the question of who does the testing and whether they are trusted. My impression is that while disputes over legitimacy or rules of succession are not that rare historically, they are usually cover for some deeper underlying problem, often religious.
Odd ideas — this seems like a worry. Historical examples are again scarce, though. Most odd ideas can be indulged as hobbies at miniscule cost to a modern nation.
The most dangerous odd idea is liberalism; such a damaging and plausible outcome that I already listed it separately. Most European monarchies did in fact succumb to liberal kings. The next most serious threat is religion. If the king adopts a minority religion, or even the majority religion with too much enthusiasm, he risks stirring dangerous levels of opposition. The Stuarts’ problems mostly stemmed from this (though the reformation in Europe necessarily made things difficult for them). My solution is antidisestablishmentarianism.
The common element in many of the perceived dangers of monarchy relate to what the intentions of the monarch will be. The intentions of monarchs seem to nearly always be to preserve his kingdom intact for his family, to be remembered as a success, and, quite often, to get laid a lot.
These motives can cause problems — heavy-handed policing employed against even remote threats to the regime, wasteful vanity projects — are common to all forms of government, particularly democracy. The failure modes that really are specific to monarchy are well-understood, and steps to avoid them have been taken — it is well-known that the chief responsibility of the young royal is to produce more than one legitimate heir at a relatively decent age.
We see this today in the non-ruling royal families of Europe, along with a relatively recent development, that elderly monarchs are routinely either abdicating in favour of their children, or less formally delegating to them. This is an important response to modern longevity. A monarch with strong family loyalty who found himself incapacitated by illness would be likely to do the same.
A tight family group provides these benefits to a monarchy, but if the family is relied on as the most trusted set of allies for the monarch, then family members are going to be competing to some extent for power and influence. This is normal, and happens under every form of government. The fact is that members of a royal family are closer to having a common long-term interest than members of other ruling organisations — political parties, civil service departments or military commands, and so are less likely to be destructive in their competition.