The Proms, Jerusalem and England's Green and Pleasant Land

In Britain, every September, there is a Last Night of the Proms - the end of the summer season of promenade concerts of classical music - and the tradition is to play Hubert Parry's 'Jerusalem', a setting of William Blake's poem. It is now something like an unofficial British national anthem. The poem speaks of

I will not cease from mental fight
Nor shall my sword sleep in my hand
'Til we have built Jerusalem
In England's green and pleasant land

With an inversion - and bearing in mind, to put it mildly, the tensions and troubles in the Jerusalem of the Middle East - bearing also in mind the famed toleration of Britain - a radical muse would be that of Britain, ideally as a secular state, retrieving some authority over Jerusalem, providing a relaxed and easy home for Jews, Christians and Muslims, to whom the city means so much, building indeed a Jerusalem of peace.

And, if we would like to speculate further, let that city in the Middle East be part of England's green and pleasant land.

True, few may support this wild speculative idea....
but wild speculative ideas may be required.