DATA WERE RECORDED ON ALL INTERNATIONAL TERRORIST EXTORTIONARY EVENTS WHICH COULD BE FOUND FOR THE PERIOD 1968-1975. THE FOLLOWING CRITERIA WERE USED: THE EVENT INVOLVED A THIRD-PARTY GOVERNMENT; THE EVENT CONTAINED AN ACTION, A HOSTAGE, AND A DEMAND WHICH HAS TO BE MET TO SECURE RELEASE OF THE HOSTAGE; THE EVENT WOULD HAVE TO BE CARRIED OUT BY A POLITICALLY MOTIVATED ORGANIZATION; THE EVENT WOULD HAVE TO ALLOW FOR A DECISION OR ACTION BY THE THIRD PARTY. THE DEFINITION OF THIRD PARTY WAS LATER EXPANDED TO INCLUDE CORPORATIONS. DURING THE STUDY PERIOD 166 INTERNATIONAL EVENTS WERE IDENTIFIED WHICH MET THE CRITERIA: 89 KIDNAPPINGS, 28 BARRICADE INCIDENTS, AND 49 HIJACKINGS. CORPORATE KIDNAPPINGS RANK AS THE MOST SUCCESSFUL TYPE OF TERRORIST EXTORTIONARY EVENT, INVOLVING 38 CASES IN WHICH 29 SUCCEEDED IN EXTORTING RANSOM. DEMANDS FOR RANSOM WERE MORE SUCCESSFUL THAN DEMANDS FOR PRISONER RELEASE. BARRICADE EVENTS HAVE BEEN RISING SLOWLY, THE USUAL DEMAND BEING AMNESTY OR SAFE PASSAGE FOR THE TERRORISTS CONDUCTING THE BARRICADE. PRISONER RELEASE WAS DEMANDED IN 15 OF THE 28 EVENTS AND RELEASE WAS SECURED IN 6. ALTHOUGH THERE WERE OVER 250 AIRCRAFT HIJACKINGS DURING THE STUDY PERIOD, ONLY 48 INVOLVED ACTION BY A THIRD PARTY. EXAMINATION OF THESE SHOWED THAT, INDEED, LACK OF SUCCESS HAS LED TO A REDUCTION IN THIS TYPE OF INCIDENT. WHEN CUBA BEGAN IMPRISONING HIJACKERS, ATTEMPTS TO GO TO CUBA DROPPED DRAMATICALLY. IN THE 21 HIJACKINGS DEMANDING PRISONER RELEASE, ALL RELEASES WERE ACHIEVED BEFORE 1971; ONLY 3 RELEASES OF 13 DEMANDS WERE ACHIEVED AFTER 1970. THIS MAY BE WHY SUCH HIJACKINGS INCREASED TO SIX IN 1972, DROPPED TO FIVE IN 1973, THEN DROPPED TO ONE IN 1974 AND 1975. THE MAJORITY OF SUCH HIJACKINGS WERE CONDUCTED BY PALESTINEAN ORGANIZATIONS. ANALYSIS FACTORS INDICATES THAT COUNTRIES WHICH IMPRISON TERRORISTS INDEFINITELY ARE MOST LIKELY TO BE TARGETS OF TERRORIST ACTIVITY; COUNTRIES WHICH REJECT TERRORIST DEMANDS ARE USUALLY NOT TARGETED AGAIN; THAT THIRD-PARTY COUNTRIES WHICH IMPRISON TERRORISTS ARE OFTEN TARGETS THEMSELVES SO THAT EXTRADITION TO THE HOST COUNTRY IS EXPEDIENT, AND THAT THE AMOUNT OF PUBLICITY GENERATED SEEMS TO BE A FACTOR IN TERRORIST ACTIVITY. (GLR)