SINCE THE DISRUPTION OF THE TURKISH-FRENCH HEROIN CONNECTION IN 1972, MEXICO HAS BEEN THE MAJOR SOURCE OF HEROIN FOR THE ILLICIT MARKET IN THE UNITED STATES. SINCE 1973, ABOUT $50 MILLION IN INTERNATIONAL NARCOTICS CONTROL ASSISTANCE HAS BEEN PROVIDED TO MEXICO. THE ENFORCEMENT EFFORT HAS CONCENTRATED LARGELY ON THE ERADICATION OF POPPY FIELDS, WHICH PROVIDE THE RAW MATERIAL FOR OPIUM PRODUCTION. APPROXIMATELY 47,000 FIELDS OF OPIUM POPPIES, COMPRISING ABOUT 14,000 ACRES, WERE DESTROYED IN 1977, REPRESENTING AN INCREASE OF ALMOST 50 PERCENT OVER THE PREVIOUS YEAR'S ERADICATION EFFORT. THE SCARCITY OF HEROIN SUPPLIES IN MEXICO IS NOW NOTICEABLE, WITH A RESULTING INCREASE IN WHOLESALE PRICES. DRUG ENFORCEMENT ADMINISTRATION DATA INDICATE THAT HEROIN PURITY IN THE UNITED STATES HAS DROPPED TO ITS LOWEST POINT IN 6 YEARS. THE UNITED STATES FINANCIAL AND PERSONNEL SUPPORT FOR THE MEXICAN GOVERNMENT IS DESIGNED TO DEVELOP WITHIN THE GOVERNMENT THE CAPABILITY TO ERADICATE ILLICIT NARCOTICS CROPS AND TO INTERDICT TRAFFICKING IN NARCOTICS, WHETHER PRODUCED DOMESTICALLY OR TRANSITING MEXICO EN ROUTE TO THE UNITED STATES. THE PROJECT ALSO AIMS TO DEVELOP SELF-SUFFICIENCY IN ALL RELATED TECHNICAL ASPECTS WITHIN A 5-YEAR PERIOD AND EVENTUAL TOTAL BUDGETARY SUPPORT BY THE MEXICAN GOVERNMENT. A FISCAL SUMMARY IS PROVIDED FOR THE INTERNATIONAL NARCOTICS CONTROL PROGRAM. (RCB)