Denouncing what it called increasing U.S. protectionism, South Africa vowed on Tuesday to cooperate with other affected nations to resist Washington's new domestic farm subsidies. "We will fight this out," Trade and Industry Minister Alec Erwin said. He said South Africa would work with Brazil, Australia, and the 18-nation Cairns group of food exporting countries at the World Trade Organization (WTO) to try to make the United States back off.