An academic from Russia, Alexander Vorontsov traveled to North Korea and what he has come back with looks like yet another information operation to drive a wedge between the United States and South Korea:

Alexander Vorontsov, (image)

In my conversations in Pyongyang, senior North Korean Foreign Ministry officials did not conceal their surprise that Seoul failed to see the huge gap in threat perceptions between American and South Korean societies. The North Koreans see growing signs, reflecting President Donald Trump’s “America First” principle, that the United States is prepared to accept the terrible loss of lives that would result from a large-scale military conflict with North Korea. In contrast, South Korean public opinion continues to believe that president Trump would never start a war in Korea—and that the tension, crisis-like atmosphere, and belligerent rhetoric are all posturing.

North Korean diplomats expressed surprise that a substantial part of the South Korean elite have missed many indications, reflected in polling data,[1] that a majority of Americans now believe that the US cannot allow North Korea to acquire a missile capable of delivering a nuclear weapon to the US mainland and that Pyongyang would order such a strike as soon as it had this capability. North Korean diplomats stressed that this is a misperception. As one opined, “it would be suicidal to attack the USA first and especially with nuclear weapons. We understand that it would be the last day of our country.” These officials were truly baffled that a majority of the South Korean population does not seem to have grasped the reality that the Trump administration, despite the risks, is inching ever closer to a preventive strike on North Korea. Pyongyang, they maintained, is under no such illusions.

North Korean experts reiterated that they are striving to reach some kind “nuclear parity” with the US, but not in order to use it in an unprovoked first strike against the American mainland.  [The National Interest]

You can read much more at the link, but the North Koreans are once again claiming their nuclear program is for deterrence only.  Unfortunately that does not fully explain why they are so aggressively pursuing a nuclear program when their conventional capabilities have proven to be an effective deterrent for decades.  Look at what they have done over the decades with killing US soldiers, taking US naval personnel hostage, shooting down a US plane, attacking the Blue House to kill the ROK president, bombing an airliner out of the sky, hijacking an airplane, shelling a ROK island, sinking a ROK ship, etc.

None of these attacks led to a retaliatory strike because of their conventional capabilities were an effective deterrent.  So clearly there is more to why they want to develop nuclear weapons so aggressively.  The theory that makes the most sense is that the true intention of their nuclear program is to separate the US from South Korea and then seek a confederation on North Korean terms.