A gem of short story in the form of correspondence between the leaders of two opposing Political Blocs whose escalation of hostilities is rapidly suppressed from a surprise third party.
After some sudden and unspecified catastrophe has depopulated England, the countryside reverts to nature, and the few survivors to a quasi-medieval way of life. The first part, The Relapse into Barbarism, is the account by some later historian of the fall of civilisation and its consequences, with a loving description of nature reclaiming England. The second part, Wild England, is an adventure set many years later in the wild landscape and society.
Consider the poor mailman of the future. To "sleet and snow and dead of night"--things that must not keep him from his appointed rounds--will be added, sub-zero void, meteors, and planets that won't stay put. Maybe he'll decide that for six cents an ounce it just ain't worth it.
Wilbur Murphy sought romance, excitement, and an impossible Horseman of Space. With polite smiles, the planet frustrated him at every turn--until he found them all the hard way!