What perceptions and missperception matter in international politics?

Answer 1

Generally, perceptions and miss-perceptions can cause countries to act in deleterious ways based of off flawed assumptions/information. Specifically though, if you are referencing Robert Jervis' book, miss-perceptions can lead to the security paradox. The best definition I have found of this is by Shiping Tang. "Under a condition of anarchy,

two states are defensive realist states-that is, they do not intend to threaten each other's security.31 The two states, however, cannot be sure of each other's present or future intentions. As a result, each tends to fear that the other may be or may become a predator. Because both believe that power is a means toward security, both seek to accumulate more and more power. Because even primarily defensive capability will inevitably contain some offensive capability, 32 many of the measures adopted by one side for its own security can often threaten, or be perceived as threatening, the security of the other side even if both sides merely want to defend their security. Consequently, the other side is likely to take countermeasures against those defensive measures. The interaction of these measures and countermeasures tends to reinforce their fears and uncertainties about each other's intentions, leading to a vicious cycle in which each accumulates more power without necessarily making itself more secure, through a self-reinforcing or positive feedback mechanism."