this book. It engages with theoretical debatesabout materialist versus post-materialist poli-tics, old versus new social movements, and thelike, but does not get bogged down in them,instead staying firmly rooted in the empiricalmaterials at hand. It also very productivelyapplies the resource mobilization theory of so-cial movements to develop an original and po-tentially powerful analysis of coalitions.Another strength of the book is that it movesbeyond static analyses of workers’ and environ-mentalists’ interests, to look at the ways in whichconceptions of interest vary over time and acrossindustries. Both cooperation and conflict arestructurally possible, Obach argues, so the im-portant issue is the way in which particular setsof organizations define their interests at a par-ticular juncture. The historical chapter is espe-cially good in this regard, reminding us thatlabor-environmental cooperation is not so new—and that it often rests on a complex set ofinterests, goals, and compromises.Obach also does a nice job of debunkingstrong cultural explanations that locate the dif-ficulty of coalition work in conflicting class cul-tures. He shows that these explanations havegarnered much of their power from a focus onthe “timber wars” in the Pacific Northwest, whileignoring many of the idiosyncrasies of this in-dustry. As an alternative, Obach convincinglyargues that much of what appears to be culturalconflict is really rooted in differing organiza-tional procedures, with the more hierarchicaland rigid decision-making style of unions beingrooted in their legal mandates.The main weakness of the book is that theevidence and the key causal arguments are notalways well connected. For instance, one of themain arguments is that organizations that de-fine their scopes more widely are more likely toengage in coalition work. This makes sensedescriptively, but as a causal argument it bor-ders on tautology, especially since having a wideorganizational range is defined as working onboth environmental and social/workplace is-sues. We are left with only hints about whyorganizations define their goals more broadlyor narrowly in the first place. The analysis oforganizational learning is also weak when itcomes to explaining