Grey-zone (international relations)

Grey-zone is a term used to describe a situation in international relations (relations between countries) where countries are trying to push the boundaries of what is seen as acceptable behavior and testing how far they can get away with it without escalating into a bigger problem or causing a major conflict. For example, country A might build a military base just close enough to the border of country B to be seen as an aggressive move, but not so close that it would look like an act of war. Country B would then have to decide how to react: do they just ignore it and hope it will go away, or try to push back and risk making things worse? That uncertainty is what makes it a grey-zone situation.