Thirty-four heads of state are gathering tomorrow in Quebec for the Third Summit of the Americans to help write a free trade pact for the Western Hemisphere. Hoards of protesters are on hand, too, concerned that the proposed pact — the Free Trade Area of the Americas — will jeopardize workers’ rights and environmental protections. Ninety-five nonprofit organizations from Chile to Canada have endorsed a World Wildlife Fund statement asking all nations in the hemisphere to commit to “sustainability assessments” measuring the environmental impact of trade rules. Meanwhile, some residents in Quebec fear that protests this weekend against globalization might become violent.