Security and defense officials on Guam say there is no imminent threat to people there or in the Northern Mariana Islands after North Korea said it was examining its operational plans for attack. Guam's Homeland Security Adviser George Charfauros says officials there are confident "the U.S. Department of Defense is monitoring this situation very closely and is maintaining a condition of readiness." The army said in a statement distributed Wednesday by the state-run news agency that it is studying a plan to create an "enveloping fire" in areas around Guam with medium- to long-range ballistic missiles. A Japanese defense paper and a U.S.