Last month, a report on cybervulnerabilities by the Defense Science Board, commissioned by the Pentagon during the Obama administration, warnedbr that North Korea might acquire the ability to cripple the American power grid, and cautioned that it could never be allowed to “hold vital U. S. strike systems at risk.”br Not long after General Dempsey made his public announcement, Mr. Obamabr and his defense secretary, Ashton B. Carter, began calling meetings focused on one question: Could a crash program slow the North’s march toward an intercontinental ballistic missile?br Trump Inherits a Secret Cyberwar Against North Korean Missiles -br By DAVID E. SANGER and WILLIAM J. BROADMARCH 4, 2017br WASHINGTON — Three years ago, President Barack Obama ordered Pentagon officials to step up their cyberbr and electronic strikes against North Korea’s missile program in hopes of sabotaging test launches in their opening seconds.