US strategy will fail if it doesn't offer DPRK the right incentives
US President Donald Trump's policy toward the Democratic People's Republic of Korea can be described as "coercive diplomacy". The United States applied "maximum pressure" on the DPRK in 2017 and used "diplomatic engagement" in 2018 to denuclearize the Korean Peninsula. Maximum pressure and diplomatic engagement may seem contradictory features, but they are actually an organic whole, with the first being the tool and the second the goal. Coercive diplomacy simply means forcing a country to stop or begin an activity by using limited force or threatening to use force.
The US has been using coercive diplomacy against other countries since the end of World War II. According to studies by scholars, including Peter Viggo Jakobsen, successful coercive diplomacy is supported by four conditions: a limited use of force or the threat to use force to compel a country to abandon its objectives; a deadline for compliance; an assurance to the target country that compliance will not lead to more demands; and an offer of incentives for compliance. Credible threat to use force and credible assurance of incentives are key to the success of coercive diplomacy.
Trump used the first two conditions well against Pyongyang, which most likely changed Pyongyang's nuclear stance.