Two from the Liddell-Hart quote:
"...Their ambitions and passion frequently carried them too far, so that the return to peace found their countries weakened rather than strengthened, but they had learnt to stop short of national exhaustion..."
True but problematical when the opponent is not another nation but a non-state entity with ill understood aspirations. That not only changes the rules, it significantly alters the playing field. Large bureaucracies and foreign affairs professionals do not adapt well to rule changes -- or to playing fields of irregular shapes.
"...And the most satisfactory peace settlements, even for the stronger side, proved to be those which were made by negotiation rather than by decisive military issue."
Always true, particularly true in irregular / COIN warfare. Quite problematic, though, when the opponent truly cannot negotiate because he is too disparate and amorphous to provide, much less enforce, a binding resolution...

Those are worrisome issues that merit some long term thinking.

This from Coined, however is a critical and important point that merits some action while the previous points are pondered and pontificated upon:
"Then you can talk about a full scale war, also when that is the case the permissive and semi-permissiv still make part of your approach towards those we categorise as opponents. We have to adapt our organisation to that.
It is also one that large bureaucracies have great difficulty understanding, much less implementing.

The prognosis, as the saying goes, is not good...