Waiting for the barbarians

While rummaging through books about the collapse of the Soviet Union, I came across a line that sent me Googling for a poem. It turned out to be 'Waiting for the Barbarians', written by C. P. Cavafy in 1904. Here are the last lines, as translated by Edmund Keeley:

Because night has fallen and the barbarians have not come.
And some who have just returned from the border say
there are no barbarians any longer.

And now, what's going to happen to us without barbarians?
They were, those people, a kind of solution.

Indeed they were! Of course we ought to remember that 1) the barbarians were indeed at the border, and in time tethered their horses in Rome; and 2) even if one set of barbarians should vanish, there might be another set waiting in the wings.