Claim. Unification cannot be achieved by material exchange, political compromise, or third-party mediation; only true love expressed as living for the sake of others can fuse two parties eternally.
Elaboration. SMM names the requirement bluntly: “Without love, oneness cannot be achieved. When uniting two into one, words alone will not work. What should there be in order for two to become united? If they became one through material things, they would separate once the material things were gone. If they became one through the introduction of a third party for a specific reason, they would separate once that person disappears. In order for two to be one eternally, there has to be love” (CSG 13.5 §3, 51-75, 1971.11.1). The method extends to geopolitics: “What is the method to bring about unification? Living for the sake of others. Then, in uniting the North and South, should we do what Kim Il-sung says? We are not doing what Kim Il-sung says. Everywhere love dwells is good and desirable, and if we stand in this good position of being able to give eternally, the North and South will be united” (ibid, 36-76, 1970.11.15). Love is the only force “that can unite the most extreme and opposite things.” The structural reason — given elsewhere in CSG — is that love alone can bridge subject-object polarity without collapsing it; hence reunification by give-and-take of love succeeds where reunification by sovereignty negotiation fails.
See also. true-love, give-and-take-action