There are basically three ways President Trump may approach his summit with Kim Jong Un:

He can issue an ultimatum: say that North Korea must completely denuclearize, allow international inspectors to verify their denuclearization, and do it in a permanent way, or else the United States would pursue a strategy to change his regime and/or use military force.

He can seek to strike a deal: try to work out the specifics of which sides gives up what at the table. This is unlikely, considering the incredible complexities involved and his explicit refusal to absorb the details of these issues.

He can initiate a process: he may decide that a summit is not be the ideal venue to solve this intractable issue for all time in one fell swoop. Rather, he may decide to use the summit to make some practical progress – potentially with agreements on a nuclear and missile freeze, declaring an end to the Korean War, establishing diplomatic offices, reducing economic sanctions, adjusting U.S. military posture on the peninsula, dismantling ICBMs, and agreeing to North Korea's eventual denuclearization – while also establishing a common foundation for future diplomacy and negotiation.

It appears that the most likely outcome is that Trump and Kim will identify some early practical initiatives, declare shared objectives for peace, normalization and denuclearization, and begin a long diplomatic process for further work –potentially with an agreement to meet again as things progress.

I remain skeptical about North Korea genuinely agreeing to complete, verifiable, and irreversible denuclearization (CVID). Kim is not going to abandon decades of work by his father and grandfather, as well as the central piece of his own legitimacy at home, in a two-hour meeting. 

Even if he agrees to CVID in theory, the devil will be in the details, what he expects in return, and verifying North Korea's compliance with its agreements. I also have deep concerns about what U.S. concessions may be needed to move down the path, such as reducing U.S. force posture in Asia and diminishing U.S. alliances in the region. Yet, I continue to believe that establishing a process – despite our doubts and worries – is the best way forward.

However, negotiation in itself is not a strategy. There is still a danger that diplomacy will fail, and President Trump may see no alternative but a military option. Lindsey Graham has said as much. While it makes sense as a negotiating tactic to present a stark alternative to diplomacy ('do a deal or else...'), in reality, I hope that the Trump administration has a Plan B in mind that doesn't involve a catastrophic military confrontation.