In any mechanical system, if your design is “lets give one part of the system all the stress” but said component is not proportionately strengthened or incentivized, it fails eventually, bringing the rest of the system down with it.
Well it's a starting point at least (see Austria or Belgium). You would then have to build more peace-keeping infra on top of it (see EU). Which highlights why it was an error to de-buffer Ukraine (also the CIS states surrounding Russia serve more or less this role, although "vassal" would be more appropriate).
Speaking of a mecanical system: In the hiearchy of sovereignity, apart from US, RU and CN all countries are somewhat buffers.
In any mechanical system, if your design is “lets give one part of the system all the stress” but said component is not proportionately strengthened or incentivized, it fails eventually, bringing the rest of the system down with it.