A global network of powerful entities, fueled in part by Wall Street, is buying up land and water around the world. This global land rush has led to wrecked wells and lost farms from Arizona to Zambia " and it risks sowing the seeds for future global conflict, according to "The Grab," a new documentary out today from Gabriela Cowperthwaite. The film follows a seven-year investigation by producer and journalist Nathan Halverson of The Center for Investigative Reporting. In part, "The Grab" argues that power is being exercised over individual landowners by a convoluted and opaque network of sovereign wealth funds, national governments and Wall Street. One critical focus of this push is Africa. Halverson interviewed Brig Siachitema, an activist in the Zambian town of Serenje, where he says foreign investors have been buying up the ancestral land of villagers and kicking them off it. Late in the movie, he presents La Paz County Supervisor Holly Irwin with evidence that the Arizona State Retirement System " her own pension fund " is invested in the project that is draining the aquifer beneath the county. Rather than fighting to protect U.S. land and food from other multinational corporations, "the governments are working for the corporations." There are enough calories worldwide to feed a growing global population, even with climate change, and even in 2050. The race to lock down resources, and governments' panic over the unrest caused by spiking food prices, risks scaling up to a war between great powers.