What was the policy of brinksmanship

The policy of brinksmanship is a policy of willingness to go to the edge of war in order to make an opponent concede.

Explanation:

When two or more countries are in conflict with one another, they often use their military's prowess as a threat to make the opposition lost their interest.

This strategy used to create a tension within the opposition based and make them think that engaging in war with the opposition actually will cost more than the value that they get from their initial interest.

Example of this would be what United States and the Soviet Union did during the civil war.  In order to fight for influence over several regions across the war, both countries continuously established military's bases that's close with one another.