In the roller-coaster ride that is U.S. diplomacy under President Donald Trump, the summit between Trump and North Korean leader Kim Jong Un is back on schedule: The two men will meet Tuesday in Singapore. While diplomacy is always to be preferred to threats and war, successful diplomacy demands planning, patience, an understanding of the party across the table and a keen appreciation of all equities involved. Pyongyang has been planning for decades for this encounter: By all appearances, Washington is scrambling. As the two men meet, it is critical to remember: No deal is better than a bad one.

Trump shocked the world when he agreed to sit down with Kim, a meeting that North Korean leaders had sought for years and had been denied. The impetuousness and risks inherent in that decision became clear as the summit date approached and doubts mounted about North Korea's commitment to complete, verifiable and irreversible denuclearization (CVID). Just two weeks ago, Trump canceled the summit, citing North Korean statements that attacked U.S. officials and showed "tremendous anger and great hostility."

Fearful of losing the opportunity to meet the U.S. president, North Korea responded with restraint and dispatched a senior envoy, Kim Yong Chol, to meet with Trump and Secretary of State Mike Pompeo to salvage the summit. After two days of talks, and the presentation to the president of an oversized letter from Kim Jong Un, Trump agreed to proceed as planned. Now the world waits to see what will transpire next week in Singapore.