The study investigated the effects of Israel's use of offensive, defensive and conciliatory tactics on Palestinian's use of terrorist tactics. Proportional hazard modeling assessed the effects of Israeli tactics on total terrorist activity by Palestinians, suicidal and non-suicidal acts of terror, and acts of terror attributed to Hamas, Palestinian Islamic Jihad and factions affiliated with Fatah. Palestinian acts of terror decreased following the construction of the separation fence, but increased during Operation Defensive Shield (ODS). However, the effects of various Israeli tactics differed for the different groups. Targeted assassinations increased Hamas terrorist activity, increased PIJ activity only if highly senior persons were targeted, and had no immediate effect on terrorist activity by Fatah-affiliated factions. ODS increased terrorist activity by Fatah-affiliated factions but had no effect on Hamas and PIJ. Several conciliatory measures were followed by periods of no terrorist activity at all by Hamas and Fatah-affiliated factions. The findings highlight the importance of considering the responses of different terrorist groups when evaluating effects of counterterrorist tactics.