WASHINGTON, Oct. 25 (Yonhap) — A preventive military strike by the United States would not remove all of North Korea’s nuclear and ballistic missile capabilities, a renowned American expert on the North Korean issue has said, while proposing economic sanctions as the most viable tool to end North Korea’s nuclear weapons program.”A preventive military strike would not destroy all of North Korea’s capabilities. It would risk a wider war that would inflame South Korea and Japan and potentially cause millions of casualties,” Michael Green, vice president for Asia at the Center for Strategic and International Studies (CSIS), said last week in Washington, D.C. in his meeting with South Korean journalists.Previously, he served as a senior director for Asian affairs at the National Security Council under former U.S. President George W. Bush.”It would also threaten the U.S. because North Korea has an ability even without ballistic missiles to transfer nuclear weapons to terrorist groups, so a preventive military strike would not get all of North Korea’s nuclear capabilities and would risk an unacceptable war,” Green noted.Diplomatic negotiations with Pyongyang would also not warrant resolution of North Korea’s nuclear problem, given the country’s track record of breaking previous agreements, he said.