SINIC AND HELLENIC UNIVERSAL STATES 659
on to the natural frontiers that here lay close within their reach was
more significant, and more ominous, than their failure to find a satis-
factory frontier in the great open spaces of Continental Northern
Europe and South-West Asia. Their performance in Britain argued an
inability or unwillingness to mobilize even a limited additional quantum
of energy or resources or both when this quantum amounted to no
more than an inconsiderable fraction of Rome's total latent strength,
and when a temporary exertion of this marginal effort promised to
bring her a permanent relief from strain. The weakness that the Romans
thus exhibited in Britain was also displayed by them in North-West
Africa; and their failure here is particularly pertinent to our present
inquiry because, as has been pointed out,1 North-West Africa corre-
sponded, in the geographical structure of the Roman Empire, to that
southern hinterland of the Sinic World in which a Sinic universal state
at bay eventually found *a natural citadel' thanks to the successful
exploitation of this region's politico-geographical potentialities by the
conscientiously thorough-going labours of Prior Han empire-builders.
In terms of human geography North-West Africa was an island; for,
wherever its coasts were not laved by the waters of the Mediterranean
Sea and the Atlantic Ocean, they were brushed by the sands of the
Sahara; and this desert, as the Romans had found it, had been a
more effective insulator than the conductive waters of the Western
Mediterranean, since the Sahara remained recalcitrant even to the
steppe-conquering technique of the Afrasian Nornads until the Romans
themselves placed a Sahara-conquering weapon in their Afrasian
Nomad barbarian adversaries' hands by introducing the camel into
North-West Africa from Arabia.* The conquest of the Sahara by
indigenous North-West African Zanata Berber Nomads,3 who had learnt
the use of the camel from Nafusa and Lawata Berber Nomad immi-
grants from Tripolitania,4 was not, however, consummated before the
overthrow of the Roman regime in North-West Africa in AJD. 429-39
by the co-operation of an intrusive barbarian war-band, composed of
Alan Eurasian Nomads and semi-nomadicized Vandals, with indigenous
barbarian war-bands recruited from the never subjugated sedentary
barbarian North-West African Highlanders. This long-delayed but, in
the event, irresistibly overwhelming assault on Roman North-West
Africa by the combined forces of convergent barbarian aggressors was
the penalty of the Romans* failure to exploit the Maghrib's poten-
tialities as 'a natural fastness* by subjugating the Berber highlanders
up to 'the natural frontier' offered to Rome by the dry shore of a then
still untenanted Sahara.5 The Romans' sole achievement in this field
was a precarious pacification of the isolated massif of the Aures; but
they did not ever effectively occupy more than the eastern half of the
Algerian Tall, and, a fortiori^ they hardly touched the Moroccan Rif
and never took even a first step towards subduing the Atlas.

This Roman record in North-West Africa was a very different story

1 See p. 658, n. 3, above.

2 See Gautier, E. F.: Les Silcles Obscurs du Maghreb (Paris 1927, Payot), pp. 162,
184, and 199-200- . f ., ,_ . 3 See ibid., pp. 197-8.

4 See ibid,, pp. 209-10. 5 This failure has been, noticed in V. v. 305.