WASHINGTON (AP) -- Global warming poses a "serious threat to America's national security" and the U.S. likely will be dragged into fights over water and other shortages, top retired military leaders warn in a new report. The report says that in the next 30 to 40 years there will be wars over water, increased hunger instability from worsening disease and rising sea levels and global warming-induced refugees. "The chaos that results can be an incubator of civil strife, genocide and the growth of terrorism," the 35-page report predicts. "Climate change exacerbates already unstable situations," former U.S. Army chief of staff...