Using coercion and force in counterterrorism can be very effective in short run, but it can be harmful to the long term goals of the counterterrorist force. This is the major advantage and disadvantage of using them.
In the short term, coercion and force can achieve the counterterrorist’s goals. To use the extreme case, when the United States uses an unmanned drone to kill a terrorist leader, that leader is no longer alive to help with the terrorists’ activities. At a lower level, putting strong pressure on people (whether physical, emotional, or economic) can get them to give you information or to act in ways that you want them to act. All of this is good for achieving counterterrorist goals.
The problem comes in the long term. Long-term counterterrorism is mostly about trying to win people over so that they do not want to support (or possibly engage in) terrorism. Coercion and force can be counterproductive to this goal. In the two examples above, we might worry that we are creating more hatred against us. If the drone strike kills civilians as well as the terrorist, it will cause more hatred. The person who is pressured may acquiesce to us in the short term, but will be looking for ways to hurt us thereafter.
Thus, coercion and force are likely to be useful in the short term, but problematic in the long term.