Generally, diplomacy with threats works much better than threats or diplomacy alone. As we said earlier, this works best if the threat of military intervention is credible and communicated clearly. In the 1800s, the threat was backed up by the appearance of large warships off the coast of the capitol city (gunboat diplomacy). Today the weapons may differ, but the threat is the same.
There are several factors that can help achieve compliance:
-The coercing state’s seriousness and demands should be clear, and preferably made before action is taken by the target state.
-The military threat should be credible.
-There should be domestic and international support.
-There should be clear understanding on settlement terms.
The coercing power should recognize that coercive diplomacy frequently leads to military conflict. If it does, intervention should be made with sufficient force to be quick and decisive. (The Powell Doctrine.)