It's still very early days to understand the true fallout from Russia's invasion of Ukraine, but I thought it would be interesting to tally a few of the estimates for the insured loss we've seen so far, all of the below come from the Insider.
Please note, I'm not endorsing any of these estimates, merely collating them for the interested reader!
Kiv Perchersk Lavra Monastery, Kyiv. @Andriy155
The Insider's estimates
These are all estimates of the gross London market exposure to the events in Ukraine.
Political Violence = $3-5bn 
Credit & Political Risk = $2-6bn (I'm assuming no double counting from PV) 
Renewables = $313m (counting Syvash and Primorskaya wind farms, but nothing further)  & 
Marine Hull war = \$ 100m- \$ 5bn (based on 200 vessels trapped, 4 reported damaged already @ $25m per vessel) 
Aviation = $12-15bn 
Low estimate = $17.4bn
High estimate = $31.3bn
Mid point = $24.4bn
Will we see insolvencies from these events?
The overall market loss of \$ 24bn, on the face of it, should be quite a manageable number for the industry. In 2021 for example, the industry absorbed something like $30bn from Hurricane Ida without any major deterioration in capital. However, there are two important differences with the Ukraine losses, firstly, these losses will primarily fall on specialty writers, who can often be smaller and less broadly capitalised than US property cat writers, but the second interesting point is that not everyone is going to have the cover they expected from their Reinsurance.
Pulling some numbers out of the air - a Lloyd's syndicate may have purchased Aviation War Reinsurance up to a RDS limit based on one of the following:
This might only have suggested they need a limit of 50m-100m, whereas now, based on the scenarios described in , they may be sitting on a 100m+ loss, which they will have to absorb net once they've used up their reinsurance. Based on a quick back of the envelope, just looking at Aviation losses, I don't think this should completely wipe anyone out or hit the central fund, but it could easily eat into capital enough that some companies are unable to continue to write next year without fresh capital injections from their parents.
I work as an actuary and underwriter at a global reinsurer in London.