In its editorial on 20 June, the paper warns of the risks for South Korea for straying too far from a close alliance with the United States.

The controversy over the remarks of top South Korean presidential security aide Moon Chung In shows how narrow the tightrope we will have to walk will be.

As the aide's indication of the possibility of scaling down the South Korea-US joint exercise made strong repercussions in both Seoul and Washington, Cheong Wa Dae (South Korea's Blue House, official residence of the head of state) rushed to play down the controversy.

Senior Cheong Wa Dae officials said on Monday that the presidential office delivered a "stern warning" to Moon that his comments do not help with the alliance with the US. They previously said Moon's words were only his personal views.

But the damage has been done. Moon's suggestion that the allies could cut back their joint exercise if the North stops making nuclear and missile provocations fuelled suspicions - here and in the US - that the new liberal administration in South Korea may give priority to appeasing the North over the alliance with the US.

The aide made the controversial comment about 10 days before President Moon Jae In tackles North Korea issues in his first summit with US President Donald Trump in Washington.

The atmosphere over the upcoming Moon-Trump talks had already become tense due to President Moon Jae In's decision to suspend the deployment of a US missile shield system in South Korea, over which, media reports said, Trump "expressed fury."

The aide also challenged a key policy Trump has been using in response to North Korea's recent provocations - sending strategic assets like aircraft carriers and nuclear bombers and submarines.

Although Cheong Wa Dae tried to play down the aide's remarks, the latest developments deepened concerns that President Moon and Trump may expose differences in dealing with the North's nuclear and missile threats.

To make it worse, the case of Otto Warmbier, a college student who died after returning home in a coma after 17 months of captivity in North Korea, has aggravated the US public sentiment toward the North.

Trump who previously called the case "a truly terrible thing," said the US condemns the "brutality" of the North Korean regime. In light of Trump's personality and style, it is not hard to believe how Warmbier's case would affect the US leader's position on North Korea.

That would narrow down President Moon's ground for seeking to engage North Korea. In fact, his aide Moon Chung In was not the only one who suggested premature appeasement overtures toward Pyongyang.

Cho Myung Kyun, the nominee for the unification minister that handles North Korean affairs, said that South Korea should think about revoking its decision to shut down factories run by southern firms in the North's border city Kaesong. That could run counter to the UN-led international efforts to toughen sanctions against the North's unceasing provocations.

Suh Hoon, director of the National Intelligence Service, another key agency dealing with North Korea policy, even mentioned the possibility of a third inter-Korean summit between President Moon and North Korean leader Kim Jong Un. Suh played a key role in both the previous inter-Korean summits - between Kim Dae Jung and Kim Jong Il in 2000 and between Roh Moo Hyun and Kim in 2007.

As things stand, however, the North seems disinterested in any peace overtures from the South. For instance, Pyongyang rejected 15 aid programmes proposed by South Korean civil and religious groups.

President Moon and his aides ought to think about where we stand after the two summit talks and the conciliatory measures that followed them - like the Kaesong Industrial Park. The North is continuing to upgrade its nuclear and missile technologies, which only months ago raised talk of war due to Trump's hard-line stance.

Unlike domestic policies, trial and error must not be allowed in national security.

How to deal with North Korea and the growing threat from its nuclear and missile capabilities is a matter of life and death. A tight alliance with the US is essential for our national security. This is true of a conservative or liberal government.

The Korea Herald is a member of The Straits Times media partner Asia News Network, an alliance of 22 news media entities.