When Washington was truly committed to de-escalating tensions with North Korea, Pyongyang responded positively, halting missile tests and demolishing several testing sites. This changed when the US began to increase its military presence in the Asia-Pacific, thereby posing an existential threat to the DPRK. Carrying out provocative drills will only escalate tensions.
Seoul and Washington have demonstrated goodwill toward Pyongyang in the hopes of creating an environment conducive towards disarmament talks for four years. However, as North Korea has failed to make good on its promises — resuming its missile tests and further developing its nuclear program — this course correction is necessary for the restoration of the readiness of the South and its allies for an attack from the North.
There's a 17% chance that North Korea and South Korea will be recognized as a single sovereign state by 2045, according to the Metaculus prediction community.