South Korea appears more insecure than ever.

North Korea recently fired a mid-range ballistic missile in a way that makes it difficult for South Korea to intercept. In response, the hard-line new US government vowed to deal with North Korea “very strongly,” with pre-emptive strikes being discussed as an option.

A day after the missile launch, Kim Jong-nam, the half brother of North Korean leader Kim Jong-un, was assassinated in broad daylight at a bustling airport in Kuala Lumpur, Malaysia. Intelligence authorities suspect Kim Jong-un as the mastermind behind the killing.

The missile launch and assassination are drawing South Korean politics into a maelstrom, with North Korea emerging as a big election issue dividing conservatives and liberals in South Korea.

Conservative candidates are drumming up the North Korea issue to highlight their security pledges to build strong deterrence, while criticizing liberal candidates’ stance on national security.

Rep. Yoo Seung-min, a presidential candidate from the Bareun Party, said, “Liberal candidates’ views toward North Korea in this grave security situation are worrisome.”

Their pledges on North Korea look risky indeed.

The most worrying is Moon Jae-in’s because he is the runaway leader in presidential polls.

“It is a deep-rooted evil to use North Korea issues for political purposes,” he said in a ceremony Thursday to launch his group of advisers on diplomacy and security.

It is wrong for politicians, usually conservatives, to overblow national insecurity and North Korean threats to swing voters to their side. Yet it is wrong, too, to underrate such issues.

Neither overestimating nor underestimating national insecurity will serve the national interest of South Korea. When it comes to security, which is directly related to the survival of a nation, underestimating threats is risky. Defense capabilities cannot be emphasized too much.

Moon reiterated his earlier position on a US missile defense system, saying the final decision on the system should be left to the next government so it can ramp up diplomacy.

He expressed concern about Korea’s worsening trade with China over the deployment of the Terminal High Altitude Area Defense anti-missile system here.

Moon should clarify what kind of diplomacy he is referring to.

Diplomacy not buttressed by military strength will be limited in making Kim Jong-un abandon nukes and missiles.

He should not forget China is North Korea’s ally and lifeline. The missile launch and the assassination of Kim Jong-nam have made Chinese opposition to the THAAD look less justifiable. Yet Beijing reaffirmed its friendly ties with Pyongyang after the assassination news was released.

Regarding the missile defense system, Lee Jae-myung, another radical would-be president of the opposition Democratic Party of Korea, went further, saying, “The Korea-US accord to deploy the system should be retracted.”

Moon said he would seek to restore trust between South and North Korea no matter how long and how much effort it will take. He should specify his plans to restore inter-Korean trust.

If he is seeking to reopen a North Korean complex where South Korean factories employed North Koreans as well as to restart trips by South Koreans to a North Korean mountain, he should say so clearly.

No doubt, trust is the cornerstone for inter-Korean reconciliation. It is necessary, but projects which would benefit Kim Jong-un should be reconsidered. It is risky to provide hard currency to a country under the control of a ruthless despot obsessed with nukes and missiles targeting South Korea and its ally, the US.

Given the atrocities committed by Kim Jong-un, whose behavior borders on madness as shown by his orders of public executions by anti-aircraft gun and flamethrower, it sounds naive to believe reasonable dialogue with him is possible. Moon said he would visit North Korea to meet Kim if elected president, but he should tell voters what he would say to Kim.

North Korea’s missile launch and the assassination of Kim Jong-nam have shifted the focus of the election landscape to the communist regime. In light of this turn of events, leading presidential candidates should detail their plans related to the North.