Katharina Zellweger : Apparent breakthrough on North Korean nukes comes at critical moment . She says the Korean Peninsula administration sees regime not likely to collapse . Ahn : North Korea 's sway could grow with food aid ; and there are signs that China influence waning . It has likely realized that nonengagement has been a complete failure . Ahn : Still , North Korea needs U.S. to lift its sanctions and to formally end Korean War .
Katharina Zellweger : Apparent breakthrough on North Korean nukes comes at critical moment . She says the Korean Peninsula administration sees regime not likely to collapse . Ahn : North Korea 's sway could grow with food aid ; and there are signs that China influence waning . Ahn : Still , North Korea needs U.S. to lift its sanctions and to formally end Korean War .