Money changes everything, right? The idea that cash flow can catalyze a movement is so entrenched that it has its own school of thought: “resource mobilization theory.” And yet. What explains the creeping dissatisfaction within what some now call the nonprofit industrial complex—the sense that the work of shaking up the status quo has turned more Dilbert than Monkey Wrench Gang?

I won’t be the first to point out that, despite more than $90 billion per year reaching NGOs worldwide, civil society has failed to deliver on much of its promise.

Plenty of research has looked at how movements come together, but the ways that campaigns lose their thunder is, as the academics say, “under-theorized.” I finally stumbled on a case study that, at a glance, didn’t seem like it could have much to say to cutting-edge activists in the rich world. But the more I dug in, the more it resonated with the after-hours venting of activist friends from Geneva to Toronto to Washington, D.C.

The story starts in the highlands of Tanzania, in East Africa, home to the Barabaig people. Today’s urban executive directors may travel like nomads, but the Barabaig are the real deal, herding livestock through an ancient round of pastures. The colonial British were the first to start taking away that land, and the dispossession accelerated after Tanzanian independence in 1961. In the eyes of the state, the Barabaig stood in the way of “modern development.”

They certainly did. The Barabaig were frontline activists of the first order: community based, direct action, and fast on their feet. When farms replaced their pastures, they burned the crops and destroyed machinery. When a security crackdown made such raids too risky, they launched legal challenges paid for with the sale of personal belongings and livestock. When their legal rights were extinguished by decree, they reached out to the world community. They got heard, too. Donor money rolled in—and within a few short years, the 30-year-old Barabaig land rights movement was effectively dead.

What the hell happened?

This is where things start to sound more familiar to activists who’ve never herded anything more stubborn than a Congressional aide. The Barabaig’s donors wanted clear lines of accountability, with the result that a small core of activists were professionalized—trained in networking, proposal writing, project management, etc. People with administrative talents found their influence rising, while grassroots organizers’ waned. Infighting over cash sapped more and more energy, and the movement’s goals shifted from the politically charged question of rights to the kinds of water-pumps-and-schools projects that look good in funders’ annual reports.

In the end, writes Cornell political scientist Kristin McKie, “donors became the movement leaders’ new constituency.”

This is not a money-is-the-root-of-blah-blah rant. Cash is an important tool, and even among land rights struggles in Africa, there are other cases where donor support helped win the day. Still, the quagmire that sank the Barabaig is instantly familiar to any observer of professional activism. McKie sketches the pitfalls as a flowchart:

funding -> professionalization -> disillusionment -> demobilization

There’s nothing inevitable about that chain reaction, of course. For every new-school group that is kicking against the pricks (think Avaaz and 350), there’s a legacy organization that scores high for effectiveness (groups like The Nature Conservancy come to mind). The question of what money costs is simply one that not enough non-profits ask.

Are your decisions to go after funding as smart, strategic, and uncompromising as the rest of your movement for change? McKie’s flowchart shows where you might want to intervene. Set clear, specific goals that donors can support—or not. Ask yourself when professionalization is targeting weaknesses, and when it’s just generating an activist version of The Office. If funders’ paperwork requirements are being met with too much loss of lifeblood, listen to your gut and run the other way. And if you need an easy way to remember all of this, I have an African proverb to help you: Don’t set sail on someone else’s star.