There is no evidence that hard-line policies reduce terrorism or even discourage political extremists. It is a given that negotiation with both types of political extremist should be undertaken, with terrorists requiring very special handling. Examples of two scenarios of airplane hijackings are given with the advice that the terrorist will be a catalyst for tragedy if a misstep is made in negotiations. This article does not present solutions, but raises awareness of the difficulties involved and the need for help, even in the realm of the exotic, along with qualified special consultants being sought to offer advice.
Government Negotiations with Terrorists: US Edition
Also:
Negotiating with Terrorists, from the Journal of Police Negotiation, 2001