We will not negotiate with terrorists

[Divinus Arma]

This is the one and main argument that is always brought forward in this context.

Mind you, I do not believe that AQ currently is a partner for negotiations - but is there actually any empirical evidence that supports the point that negotiations lead to more terrorism compared to refusing to negotiate?

Sure. Hostage taking in 3rd World countries and in Iraq. It's a regular business and people regularly pay up. So they continue to take hostages to get ransom.

Article 1 (CNN) (Hostage taking in Iraq)


Department of State: Policy

US Government Responsibilities When Private US Citizens Are Taken Hostage
On the basis of past experience, the US Government concluded that making concessions that benefit hostage takers in exchange for the release of hostages increased the danger that others will be taken hostage. US Government policy is, therefore, to deny hostage takers the benefits of ransom, prisoner releases, policy changes, or other acts of concession. At the same time, the US Government will make every effort—including contact with representatives of the captors—to obtain the release of hostages without making concessions to the hostage takers.

The Heritage Foundation Discussion on Phillipnes decision to give in to terrorist demands.

Edit: BTW, this has been American Policy ever since the retarded Carter Administartion: Reagan, Bush #1, Clinton, and Bush #2 all agree.