TOKYO -- The withdrawal of Victor Cha as the next U.S. ambassador to South Korea due to his disagreement over a limited strike on North Korea, shows just how real the possibility of a preemptive strike is within the Trump administration.
And while North and South Korea have agreed to march under one flag at the opening ceremony of the Pyeongchang Winter Olympics and Paralympics, it is probably safe to assume that tensions will be ratcheted up again as soon as the games are over.
According to U.S. government analysis, Pyongyang may complete work on a new intercontinental ballistic missile capable of reaching the U.S. mainland by the end of this year.
Such a development would take the crisis to a tipping point and the Trump administration would have two policy options to choose from.
First, it could accept the reality that North Korea will not likely give up its ICBMs and work to find a way to deter the regime from using them -- backed by Washington's overwhelming military superiority.
The second option would be to launch a preemptive strike to eliminate the threat.
Debate on which would be the best course of action is now heating up among U.S. security officials and experts. When asked, people both inside and outside the government were roughly equally split between those for and those against preemptive military action.
One security expert remarked that opinion is so finely balanced within the administration and security policy community that it is impossible to predict which direction the White House will take.
The arguments against center on a belief that military action would be considerably more difficult than what many imagine and that the risks far outweigh what Washington stands to gain.
Many North Korean nuclear facilities are located underground and it is believed the regime now possesses mobile missile launchers. This means that locating targets would be far from straightforward, many argue.
If the U.S. were able to pinpoint their exact locations and conduct airstrikes, the response would almost certainly lead to all-out war.
The South Korean government is vehemently opposed to military action for that very reason. Estimates show that tens or possibly hundreds of thousands of casualties would result from a full-blown conflict.
A former senior Washington official said that war might have been a realistic option three years ago, but should now be ruled out due to the development of North Korea's weapons since then, and the risk posed to Japan and South Korea.
Those opposed to preemptive action stress the need to make it abundantly clear to Kim Jong Un just how ferocious the U.S. response would be to an attack on its territory or its allies. To strengthen deterrence, many call for more frequent deployment of nuclear-capable bombers and submarines in Northeast Asia to force home the point.
In contrast, experts in favor of military action believe it would not be as costly or dangerous as many people assume. A strategist close to the U.S. Defense Department provided a typical assessment.
For one, they argue, U.S. intelligence has managed to identify the locations of North Korea's main missile facilities. Movement of mobile launchers can be tracked to a certain extent by intercepting the regime's communications.
They also claim that the estimates cited for the impact on South Korea were calculated in the mid-1990s. U.S. military capability has since developed exponentially and North Korean forces could be defeated before anywhere near the number of casualties reached those figures.
In addition, many feel the South Korean government has built underground nuclear shelters across its territory and conducted numerous emergency drills. The country has put systems in place that are significantly more resilient to artillery and missile attacks than they were in the 1990s, according to the strategist.
The underlying fear for those in favor of striking first is that North Korea would become increasingly belligerent once it had developed the new ICBM.
Another former senior U.S. government official warned that if Pyongyang were to complete the missile's development, it would intensify its provocations in the belief that Washington would be left powerless.
North Korea could, for example, carry out terror strikes or limited attacks on Japan and South Korea to push the U.S. to withdraw its military presence from the region, the official said -- adding that U.S. alliances with Japan and South Korea would then effectively collapse.
There are also concerns that North Korea will export nuclear missile technology to other regimes -- it has already done so to Syria.
Which option the administration takes will depend on two crucial variables.
The first will be which camp gains the upper hand among Trump's key aides. Secretary of Defense Jim Mattis and Sectary of State Rex Tillerson are inclined to keep pushing for a peaceful solution, while National Security Adviser H.R. McMaster reportedly believes North Korea cannot be deterred.
The other, more decisive, factor is the stance taken by Trump himself, but if there is one thing that Washington insiders all agree on it is that the president can be unpredictable.
Foreign ministers from 20 countries gathered in Canada in mid January and agreed to further cooperate in dealing with the crisis. Nevertheless, when it comes to decision time, we can expect one that puts America first.