In an apparent first, the United States on Thursday charged two Cuban migrants with threatening U.S. Coast Guard officers who were trying to stop the men earlier this month off Key Largo, a confrontation broadcast live around the world.Federal officials said they knew of no other instance in which such charges had been brought against Cuban migrants who reached U.S. soil after eluding the Coast Guard.If convicted, Javier Morales-Molina, 26, and Reinaldo Molina-Morales, 29, face up to 20 years in prison. They also could be disqualified from becoming U.S. citizens.Attorneys for the men accused federal authorities of trying to make...