Of these choices, the better choice is to pursue “soft power.” This does not mean that there is no room for preemption, but it does mean that soft power is ultimately going to be more important and more widely applicable.
The most obvious reason for this choice is that we simply cannot act preemptively in many of the countries that foster terrorism. As an example of this, the 9/11 hijackers were almost all from Saudi Arabia. We feel that Saudi Arabia’s official policies encourage the dissemination of a form of Islam that tends to be stridently opposed to the United States. However, Saudi Arabia is a very important ally of ours. We cannot possibly attack it in any way.
What this means is that we need to use soft power. We need to, if possible, act in ways that allow us to have better relations with the countries that are the sources of terrorists. More importantly, we need to try to improve our image with the people of those countries since it is they, and not their governments, that end up supporting terrorism.
There will be some limited role for preemption in lawless areas such as Yemen and the tribal areas of Pakistan. However, the times and places in which preemption is possible are not widespread. We need to be able to make it so fewer people want to be terrorists.