Following the Winter Olympics, South Korean President Moon Jae-in indicated he was ready to talk to North Korea and engage in diplomacy. And while Vice President Mike Pence – who earlier announced severe sanctions on the North –first signaled a willingness to talk, he quickly seemed to change course.

President Trump further indicated that he is considering a preventive military strike on the North if the sanctions failed to denuclearize the communist nation. But such a so-called “bloody nose” strike against North Korean missile sites and nuclear facilities stands an excellent chance of becoming a bloody disaster.

China won't tolerate an unprovoked attack on North Korea, and President Moon will not support the use of South Korean forces as part of a U.S. military strike against North Korea.

South Koreans loathe the regime of North Korean dictator Kim Jong Un. But very few think that initiating a war on the Korean Peninsula will hasten reunification, let alone lead to lasting peace. In fact, 59 percent of South Koreans oppose a pre-emptive strike on North Korea’s nuclear facilities.

Consequently, if President Trump authorizes military action against North Korea, the most probable outcome will be war with China and the immediate expulsion of U.S. military forces from South Korea. President Moon will have no other choice if he is to avoid conflict with China.

And, contrary to expectations in Washington, Japan will decline to participate in Washington’s “bloody nose” extravaganza in any meaningful way. Tokyo will privately welcome a conflict that removes North Korea from the map, but will not put the Japanese home islands at risk to help Washington in its war with China.

The net result will be embarrassment on a global scale for Washington and the American people. The Trump presidency could well be destroyed.

On the other hand, it’s useful to point out that President Xi Jinping of China has actually cooperated with Washington to push North Korea to the brink of economic implosion. Xi has told Kim Jong Un that if he attacks his neighbors or the U.S., Beijing will not assist North Korea in any way.

The importance of Xi’s stance to U.S. military planners cannot be overstated. Military planning is always based on a mix of known capabilities relating to friendly and opposing weapon systems, as well as unknowable aspects of a potential opponent’s behavior. Predictably, in American military planning untested assumptions are often frequently shaped by wishful thinking.

Fortunately for the U.S., President Xi has taken precautions to disabuse Washington of any wishful thinking. If America initiates hostilities against North Korea, China will not sit on the sidelines.

According to South Korean sources, if we attack North Korea the Chinese People’s Liberation Army’s Northern Theater Command is preparing the Chinese 78th Army Group for intervention on the ground to cope with the potential collapse of the North Korean state.

The Northern Theater Command in Manchuria also includes the 79th Army Group. Together, the two Chinese Army Groups positioned in Manchuria field 855 tanks, 819 Infantry Fighting Vehicles, 200 self-propelled guns, rocket artillery, missile defense units, support troops and several hundred attack aircraft – a force of roughly 300,000.

None of these points suggest that America’s nuclear arsenal could not quickly and thoroughly erase the North Korean state from the map. While that’s something that Washington can accomplish, a high-end conventional conflict with China on the Korean Peninsula is a contingency for which the U.S. armed forces are not prepared.

Any use of nuclear weapons to compensate for U.S. conventional military weakness – regardless of yield – would likely trigger a nuclear exchange with China that no sane person wants.

It is time to reconsider the wisdom of military action against North Korea. In their first meeting, President Moon asked President Trump to accelerate the transfer of wartime command of all Korean and U.S. armed forces on the Korean Peninsula to a Korean Army four-star general. President Trump was perplexed.

President Trump’s advisers had not prepared him for the question. For decades, a U.S. Army four-star general has exercised absolute authority over the South Korean-U.S. Combined Forces Command, the warfighting headquarters responsible for the defense and, if necessary, the defeat of external aggression against South Korea.

President Moon is the latest South Korean leader to conclude that without unambiguous South Korean national command authority over the armed forces on its soil, South Korea is not really a sovereign nation. He has a point.

The truth is that Washington is not equipped to “solve the problem” on the Korean Peninsula, largely because the problem is not ours to solve. South Korea is a brilliant success story. Now the United States mission on the Korean Peninsula is complete.

Seoul, not Washington, must now work with Beijing and Tokyo to solve the problem. For Washington, Step One is to signal American support for President Moon’s initiative of an inter-Korean dialogue.

Step Two is to turn over command of the Combined Forces Command to a South Korean four-star general as soon as possible. Make it clear that the destiny of the South Korean people rests in their own hands.