Here's another tidbit about the Peru Free Trade Agreement (PFTA).  Chapter 10 of the PFTA allows multinationals to sue local government to overturn laws the companies don't like.  This is the NAFTA model.

A letter by environmental groups spells it out (PDF link):

Harmful Anti-Environmental Lawsuits: The FTA’s Investment Chapter (Chapter 10) contains provisions like those in CAFTA and NAFTA that would allow foreign investors to challenge health and environmental regulations for compensation before international tribunals, bypassing domestic courts. The United States currently faces 12 active NAFTA investor-state cases.

Worse, the agreement provides foreign investors even greater rights to challenge environmental laws than CAFTA does. CAFTA gave investors the right to file suit against alleged breaches of natural resources contracts. The U.S. - Peru FTA expands these rights by broadly defining natural resources contracts to include every aspect of the extractive, productive and marketing processes. These new rights would enable multinational corporations to attack legitimate attempts by communities to protect their health and environment even if their activities are only tangentially related to natural resource extraction. For example, communities suffering from water pollution and chemical exposure due to Peru’s large mining industry are pushing to strengthen laws that regulate mining and oil exploration. The U.S. - Peru FTA’s investor rights provisions threaten these efforts, and could chill future attempts to improve environmental conditions. In addition, the agreement gives corporations the right to challenge U.S. government decisions over oil and gas royalties and
other domestic regulations.

Trade attorneys in international tribunals decide whether to strike local laws.  Multinationals turn loose their lawyers on the counsel for the local community that just voted against property tax increases and has a budget crunch.