Oicur, excellent point. In certain scenarios/reality appeasment is used. If appeasement isn't applicable (ie people who murder kids/blow up planes) then something that goes bang might be needed ie a standoff missile/SAS/F111. Its all about options.
If you appease a terrorist they will want more. If you don't appease someone who wants something they will then consider becoming a terrorist. The fact that places that terrorists considered safe and friendly keep getting invaded gives notice that even they have a price to pay now. I don't like it, I'm sure you don't like it but governments need options which include hardware when diplomacy fails.