GIBBON ON FALL OF ROME IN THE WEST 75I
forces detailed for the defence betray their trust by delivering the attack ?
And what chance would Europe have of reviving and flourishing in an
American city of refuge if the Power that had driven 'the remains of
Civilised Society' out of the Old World and across the Atlantic was, not
'the Tartar hordes', but a sedentary people equipped with the most
recently invented engines of a Western military technique?

Experience indicated that Gibbon's confidence in the inviolability of an
American asylum for the Western Civilization would have been justified
if—but only if—the aggressor's part had been played in reality by those
arrested Nomad riders who had been cast for it in Gibbon's imagination.
If the Continental Power that was under suspicion in A.D. 1952 of
entertaining designs of world-wide conquest had been, once again, the
Mongols, the peoples of the Western World would assuredly have had
better reason this time for counting on the survival of their own dis-
tinctive culture than they had had in A.D. 1238, when they had been facing
the prospect of a Mongol occupation of the West European peninsula of
Asia without having any reassuring Transatlantic asylum at their backs.
In A.D. 1952 they could have taken comfort in reminding themselves
that in A.D. 1281 the forces of a Mongol Empire, which at that date had
been mistress of the Continent from the shores of the Pacific Ocean to
the shores of the Persian Gulf and the Baltic Sea, had been thrown back
ignominiously from the beaches of Japan;1 for a cavalry Power which
had proved impotent to conquer a cluster of small islands separated from
the Continent by only a hundred miles of sea at the nearest point would
have had no prospect, if she had occupied the European coastline of the
Continent that the Germans held in June 1940, of being able to conquer
the great island of North America on the farther side of a nearly two-
thousand-miles-broad Atlantic Ocean, or even the sister island of South
America, which was divided by not less than sixteen hundred miles of
sea from the Continent at the Straits of Dakar, where the westward bulge
of Africa approached closest to the eastward bulge of Brazil. Indeed, the
fiasco of Qubilay Khan's attempt on Japan suggests that even the twenty-
miles-wide Straits of Dover, which had foiled Napoleon and foiled Hitler
when the local Continental war-lord of the day had had the whole of
Europe under his command, might have proved impassable for Qubilay
Khan in spite of his commanding the Asiatic mass as well as the Euro-
pean extremity of the Continent. But the historic immunity of the isles
from conquest by Continental war-lords had been due to the compara-
tive innocuousness of even a sedentary community's most formidable
weapons of offence until a hundred years and more after the date at which
Gibbon had been writing; and no one who had lived through the war of
A.D. 1939-45 could be blind to the truth that, since then, times had
changed. The weapons with which Hitler had come within an ace of
conquering Britain, and with which the combined forces of the United
States and the British Commonwealth had succeeded thereafter in con-
quering Hitler's vaunted Festung Eiaropa, were indications that in a
future world war the conquest of North America might not be beyond
the reach of a Power controlling the aggregate resources of the Old World
1 See IV. iv. 93.