III. SOME ASPECTS OF THE UNITED STATES-CANADIAN EXPERIENCE .........506 A. The Need for International Cooperation .. 507 B. The Role of Legal Prohibitions and Remedies . 511 C. Institutional Structure 518 D. Determining Objectives .........521 E. Apportioning Burdens 528 F. Coordination . . . . . . . . . . . . . 531 G. Implementation 538 IV. PROSPECTS AND PROBLEMS ......546