North Korea may present the greatest immediate security challenge for President Donald Trump's administration. The "hermit kingdom" has tested intermediate-range ballistic missiles and assassinated President Kim Jong-un's half brother using an illegal chemical weapon on foreign soil.
In recent years, it has shelled South Korean islands, sunk a South Korean ship and conducted multiple tests of nuclear weapons with the power of 10 kilotons. For reference, the bomb dropped on Hiroshima was 15 kilotons.
The North Korean threat to South Korea and the 28,500 U.S. troops stationed there isn't just nuclear. Seoul is only 35 miles from the Demilitarized Zone — and just beyond the mountains visible from the DMZ are thousands of pieces of artillery capable of inflicting tremendous damage on South Korea.
There are many ways Trump could handle Pyongyang. Here are just a few possibilities.
An American withdrawal
Trump could follow through on his campaign threat to withdraw U.S. forces from South Korea. In theory, this could significantly reduce, if not eliminate, North Korea's threat to the United States. In practice, it would have dire worldwide consequences — similar to what would happen should America fail to deliver on its commitment to defend the Baltic states.
Locally, it would embolden North Korea to pursue an even more aggressive position against South Korea.
The Trump administration has taken steps to demonstrate that an American withdrawal is highly unlikely; in fact, it costs the federal government less to house troops in South Korea than it does to house them in the United States.
Beginning in 2003, the United States, South Korea, Japan, Russia, China and North Korea have intermittently met in the so-called "Six-Party Talks" in an attempt to negotiate Pyongyang's denuclearization.
The difficulty in negotiating with North Korea is that it has a long history of both negotiating in bad faith and formally withdrawing from its commitments. Additionally, any negotiated settlement would require substantial commitment from China at a time of tension with both the United States and with South Korea.
Trump has said he would talk directly to Kim Jong-un, who endorsed his candidacy; however, without Chinese assistance and a dramatic change in behavior on the part of North Korea, negotiations may not prove fruitful.
The United States could escalate the conflict with South Korea in a variety of ways. It could threaten to launch — or actually launch — minor or major retaliatory retaliatory strikes against North Korean targets if Pyongyang conducts further missile tests or detonates additional nuclear devices.
The United States could also attempt to enforce sanctions by mounting a full naval blockade against North Korea and forcibly board ships bound for North Korean ports. These actions would require coordination with South Korea and could go far beyond what Seoul would be comfortable with.
The situation on the Korean peninsula is always in flux. There have been, however, some consistencies in U.S. policy, including the mutual defense treaty with South Korea, the sanctions regime on North Korea and a general willingness to return to Six-Party Talks.
Unfortunately, the status quo also leaves South Korea open to occasional attacks and the region subject to additional missile tests. The calculation for the United States is that Kim Jong-un is fundamentally rational and would never attack the U.S. homeland or mount a full-scale attack on South Korea — because it means Pyongyang would be obliterated.
This wait-and-see approach could lead to anything from more advanced North Korean arms to a North Korean collapse. The unfortunate reality of the North Korean situation is there are no easy answers, and some international problems may not have solutions.
One thing is for sure, though: The North Korean problem isn't going to solve itself.