The US ship deliberately sailed near one of the Beijing-controlled islands in the hotly contested waters
US military has technology that can robotically strike targets, but there are ethical questions about such strikes
The National Marine Fisheries Service is investigating the death of two dolphins found washed ashore in California
Warning comes as naval officials from both countries prepare for talks over South China Sea tensions
Despite China's anger, the US says it plans to send more warships to disputed waters claimed by the Chinese
USS Lassen sails past disputed Spratley Islands, which Beijing claims
Dolphin strandings have been linked to sonar use, but some scientists say that banning it won’t protect marine mammals
Obama says he told China’s president in September he had ‘significant concerns’ about the artificial islands
Agreement limits or bans midfrequency active sonar and explosives in areas near Hawaii and California
The move comes after attack in Chattanooga, Tennessee, claimed the lives of four Marines and a sailor
