Several posters have mentioned that the shoot to kill policy is no good if the individual with the bomb has a "dead man's switch", and that terrorist organizations will adopt that, if they haven't already.   Think about that for a moment.

A dead man's switch has to be held open. That means that the carrier has to maintain a constant muscle tension to hold the switch. If I were a terrorist leader/planner I'd be very shy of that approach, because of the possibility--nay, the likelihood--of the operative's stumbling, or having a sneezing fit, or being bumped in a crowd, maybe just startled, his switch hand getting tired and just wanting to shift his grip, or even just his attention wandering. and then what do we get? We get an impressive explosion in the wrong place, before the operative gets to the target. Then we've lost an operative, we've lost our bomb, we've lost surprise.

I really don't expect to find them using a dead man's switch.

Dave Oesterreich