Not easy to achieve though.

If one or more parties are "responsible" then public sentiment (amplified by social media) will bring the pitchforks.

That translates to political support and basically guarantees the election or increased support for certain types of politicians and response, which in turn will impact diplomacy.

It would take some supreme social engineering to get society at large to accept the idea of a blameless post mortem. It's really not part of the broader cultural lexicon. Even companies struggle and they are much smaller and simpler systems.

Responsibility and liability are intrinsically linked in the public mind.