Interpreting private motives under a reign of terror is notoriously hard, but the right answer must surely be that it does not matter.

Wet steam is notoriously hard to use in a traditional steam turbine because at lower temperatures water droplets form and cause damage.

And guerrilla wars are notoriously hard to win.

It is notoriously hard to make a sequel as good as the original.

They can remain volatile for decades and are notoriously hard to find and remove when conflicts end.