If the Sleeping King Arthur was to awaken and return to save Albion, as some legends suggest he will; then he cannot save us in the way a King might save his people in the past - by uniting and leading them with irresistible force to escape the yoke of evil rulers; to initiate a Golden Age of peace, plenty, beauty and Godliness.
Such a King could not save modern Britain because many, perhaps most, people do not want to be saved. Taking cue from their leaders; the inhabitants hate themselves and their country, and actively seek (by multiple means) to disparage its people and forward its destruction
For a start, the Men of Albion do not want beauty or Godliness - only pleasure and comfort.
Also, they do not regard their current rulers as evil - indeed, because they have rejected God, modern Men neither understand nor believe-in the reality of genuine evil (regarding 'evil' as merely selfishness).
Any returning King would find more people against, than with him; and those who were with him so fear-full and this-worldly as to lack the courage to take any significant personal risk or suffer even short-term inconvenience. They will not even risk other people saying they aren't nice.
What we have now is very purely a spiritual war, and the problem is that few people recognize the reality of the spiritual realm.
Indeed, the essence of the spiritual war is exactly about this denial. One cannot take sides in the war of Good versus evil, God versus the demons, until these are known as realities.
So the nature and validity of any returning Good King would itself be denied. He would be interpreted as a (reactionary) political leader merely, aiming at material benefit merely; selfishly seeking the Good of Britain merely.
Nonetheless, the Rightful King can return - but not as a mass leader; and not to impose his will on the nation.
He can return, but in the spiritual and not the material realm.
He can return, but not to conquer and overwhelm the unwilling and indifferent - but must be asked and welcomed by choice of one person at a time.
The King can return into the hearts of Men, to fortify and encourage, to provide understanding and guidance. He would unite and direct the spirit - not the bodies - of Albion.
What the King would rescue us from is passivity, un-consciousness and denial of God and the immortal soul.
Hence, the Awakening King must be invited into your human heart and mine, each by a deliberate and personal act of decision.
And the goal will be to save the spirit of Albion - to save it for that eternity into-which all will be welcomed who truly desire it.