Thanks for this interesting review of Williams'
book. 

More
than twenty years after the onset of serious research on the relationship
between human exploitation of natural resources and violent conflict, we should
bury once and for all the simplistic assumption that scarcity or abundance of
any resource leads directly to conflict.  In fact most scholars have long
ago dumped this idea in favour of more nuanced multi-causal explanations or “recipes”,
though it still finds traction in simplistic quantitative studies, with some
economists, and among policymakers with an agenda to push. (The 40% figure, for
example, should be cast aside because it says next to nothing about conflict causes
when examined in detail.)

The
real question is what precise causal role human exploitation of resources has
on the specific causal mechanisms that drive violent conflict and on the different kinds of conflict in different places.  The review above seems to offer only hints about Williams' views on
this – resources are conceptualized as “immediate drivers”, “triggers”, “at the
heart” of conflicts and thus important, etc. There is work out there that explores the
question of the causal role of human exploitation of natural resources in
causing conflict, and I wonder if Williams engaged this work? What of the claim
from some political ecologists studying African conflicts, for example, that valuable
and lootable resources are not important in conflict “onset” but instead important
for determining “conflict duration” and “persistence”? 

In
the end, I get the impression that Williams sees natural resources like INUS
factors, though he’s perhaps not explicitly saying so – an insufficient but necessary component
of a condition that is itself an unnecessary
but sufficient cause of conflict.”  Though this is probably correct from a
causality perspective, I think that we need to know more about the specific causal mechanisms at work in different conflicts if we aim
to design effective policy interventions.