Defense Secretary Jim Mattis indicated this week that the U.S. will lift a suspension of joint military exercises with South Korea. This announcement, in addition to President Trump's recent cancelation of his State Department's visit to Pyongyang, goes against what Peace Science tells us about the importance of granting concessions and avoiding provocations during intense negotiations.
Following the Trump/Kim Singapore Summit, the U.S. canceled their upcoming "war games" with South Korea. The New York Times and peace science agree that early concessions can lead to big payoffs when denuclearization is on the negotiating table.
Increasing the number of democracies in the world does not affect the number of wars until democracies reach 60% of the global governments.