Washington’s withdrawal of Korea expert Victor Cha from consideration for ambassador to South Korea shows US President Donald Trump’s North Korea policy is much more hard-line than expected.

Cha had all but been officially nominated to be Trump’s first ambassador to South Korea, with Washington asking for Seoul’s diplomatic consent to his appointment last year.

But his nomination did not occur. It is rare for Washington to withdraw an ambassador nominee whom Seoul had already signed off on. The question is why.

Media reports said that Cha had expressed opposition to the idea of the US undertaking a “preventive war” against the North, known as a “bloody nose” strike.

Cha said in a contribution to the Washington Post, published shortly after news on his withdrawal broke out, that even a limited strike could invite military retaliation from the North.

He said that an evacuation of 230,000 Americans in South Korea would be virtually impossible if the North responds with counterstrikes.

In Washington, Cha, senior adviser at the Center for Strategic and International Studies, is regarded as a “hawk,” who has stressed strong sanctions and pressure against the North.

If his nomination was removed due to his differences with the Trump administration over its North Korea policy, it would not be hard to guess how serious the US is about the military option. His withdrawal could have considerable implications regarding US-Korea coordination over their policies on North Korea.

Cheong Wa Dae must think about the meaning of Cha’s withdrawal seriously. Washington could nominate a more hard-line candidate who is ready for a preventive strike.

The “bloody nose” strategy cannot but impact the Moon Jae-in administration’s plan to use inter-Korean dialogue as a stepping stone to talks between the US and the North.

The Moon administration should review its policy to appease Pyongyang over concerns that it could play into the hands of the North.

With the opening of the PyeongChang Olympics six days away, the US is weighing hard-line options it will use after the Olympics.

Washington knows Pyongyang is trying to ease sanctions and drive a wedge between the US and South Korea. The North is trying to raise expectations for dialogue by participating in the Olympics, but, on the other hand, it is preparing a military parade to show new weapons which could threaten the US.

If things do not move as he intended, North Korean leader Kim Jong-un would likely play brinkmanship again with nuclear and missile provocations. Then, the US will likely wield a stick, possibly a preventive strike.

Trump has threatened to use a military option if necessary.

CIA Director Mike Pompeo on Tuesday told BBC News that North Korea could have a nuclear missile capable of striking the US “in a matter of a handful of months.” He said that the CIA provides to Trump options including non-diplomatic means.

However, the “bloody nose” strategy, though its concept is still unclear, would cost a ton. It does not guarantee Kim will not retaliate. Prudence is required. Former Secretary of Defense Chuck Hagel called the option a “gamble” with millions of lives.

Sanctions on North Korea are just beginning to show effects. Now is the time to turn up sanctions, not to go on military adventures.

Washington probably knows this, but could be seriously weighing military options apparently because it does not think sanctions are sufficient to force Kim to give up his nukes.

And yet it is hasty and dangerous to try military actions now. The South needs to persuade the US through their alliance that the only way to denuclearize the North lies in sanctions to the extent that it cannot but come to denuclearization talks.

To do so, it is imperative to keep in step with the US and maintain mutual trust. Seoul cannot be passed over as the US takes actions against the North, whatever they are. In the meantime, the Moon administration must try to prove sanctions are effective in bringing Pyongyang to dialogue.