Britain's huge exposure to Ukraine debt - private bonds, loan guarantees etc.
Solutions? Defeat Russia and use reparations to repay was one dream that keeps being hindered by reality. Extend and pretend, conflict escalations and general chaos are others.
Example of escalation being considered by NATO / UK Great Game players - target Russia's shadow oil fleet. Lots of geopolitical and economic implications if that is tried and responded to (oil price to $200+?). Middle East risks are in addition to this.
No wonder Boris and his ilk are so enthusiastic for the war.
