Does a democracy that cannot defend itself deserve to survive?
It depends on how you read “deserve”. There are different arguments for the legitimacy of democracy, in contrast to forms of oligarchy (rule by the wealthy few) and autocracy (rule by one).
If we are social Darwinians, like many amongst the followers of the new autocracies, the answers is a clear “no”. Fact makes right. So, if a democracy falls to an autocrat, it deserves to fall.
For supporters of democracy, you certainly want your regime to be able to defend itself. One argument of autocrats is that democracies foster weakness and effeminacy. They can’t fight. So they deserve to fall.
(Some neoNazis will tell you that it was only Soviet autocracy that could have stopped Hitler in WW2, for instance).
The only rebuttal of this position, as with the greatest generation, is to show that regimes based on the free consent of the governed can be very strong. Athenian democracy provided a model, until it was undermined by demagogues and the oligarchic faction.
But, let’s say, as in America in late 2024, that your democracy has failed. It has been given a decades’ warning of wolves at the gates, and its legal system has failed to so much as put the insurrectionist before a court, whilst allowing its media sphere to so corrupted by well-funded…