The Only way to defeat terrorism is to fight terrorism whenever and wherever it shows its head, and to never let up on those who would use terror to forward their goals.
Stopping terrorism is not like gambling, in poker there are different variables that can affect the outcome but it fighting terror the only way to win is to fight to the end.
Many people thing that the terrorist feel they have been wronged by something or someone and that giving them something will end the fight be it land or money, but history has repeatedly shown us that by appeasing the terrorists we are only giving them what they want, and prolonging the fight. They will continue to take everything they are given but they never stop wanting more.
An example of this is clear in the Israeli- Palestinian conflict. Israel allows the PLO to return to the west bank and Gaza and form the Palestinian Authority, Israel supplied weapons and the Americans provided training to the Palestinians so they could start a army to fight crime and terrorism.