The Chinese military’s nonnuclear missiles have “the capability to attack” and close down five of six major U.S. Air Force bases in South Korea and Japan, an unpublished government report says. China’s improved inventory of short- and medium-range missiles provides a “dramatic increase” in its ability to stifle U.S. military operations in the western Pacific, according to excerpts from the draft of the 2010 annual report that the U.S.-China Economic and Security Review Commission is scheduled to release on Nov. 17. China’s current force “may be sufficient” to destroy runways, parked aircraft, fuel and maintenance facilities at Osan and Kunsan...