Oil and Wafer in Sudan 197and outlying regions of the country, including some parts of the geo-
graphic north."8The drainage basin below the junction of the Blue Nile and White Nile, in
contrast to the gradual succession of ecological gradients in West Africa, pro-
vided a formidable barrier to interaction for the southern Sudanese. One set
of forces spawned by the isolation below, and another driven by the external
influences accruing above began to reach a critical threshold during the early
1800s. The result was a struggle between centralising institutional interests
concentrated at the junction of the White and Blue Niles and centrifugal
forces embedded in the wider environment.
Specific aspects of these centralising forces and decentralising initial con-
ditions periodically resurface within the conflict cycle. State organisation,
modern economy, and external linkages generally support centralising ten-
dencies. Corresponding environmental forces derive strength from the
region's cultural diversity, localised ethnic organisation and indigenous polit-
ical traditions, and subsistence strategies varying across ecological niches.
Sudan's north-south conflict svstem is therefore the oroduct of the inabilitv
to resolve tensions generated by these environmentally created polarities.
Unpacking the variables along these lines separates ecological determi
nants from the identity and religious aspects of the conflict. 1dentity and reli-
gion have been used by both sides to mobilise their internal populations and
to attract external support, yet are a feedback from the environmentally cre-
ated north-south poles. Viewed through this lens, the battle over the control
and extraction of resources - be they ivory and humans, or timber and oil -
take analytical priority over other factors of race, religion, and the African-
Arab dichotomy commonly cited as determinants of north-south enmity.9
The larger pattern of conflict across Sudan thus reveals demographic and
environmental forces operating underneath the political and social chaos.
Decreasing rainfall in pastoral areas, environmental degradation in agricul-
tural islands, and technological-economic stagnation are over time combining
to intensify ethnic conflicts over subsistence resources in both the south and
the north.ID
Northern communities and so-called 'neutral' minorities have increasing-
ly engaged in struggles over land and natural resources since the Sahel
famine of 1974-76. Most conflicts involve ethnic dyads: Baggara raids on the
indigenous inhabitants of the Nuba Mountains; Rufa'a nomads versus Gamk
and Uduk farmers in the Ingessana Hills; 'Arab' tribes' clashes with the Fur
in the Jebel Marra Massif region; and the Rashaidah pastoralists encroach-
ment on the Beja.
Sudan's estimated annual population growth during the 1990s is estimat-
ed to fall between 2.5 and 2.8%. Even in the south, where mortality from war
and famine has claimed hundreds of thousands of people, such Malthusian