News from the BBC today:
South Korea has launched its biggest-ever anti-submarine exercises, the military says, despite warnings of retaliation from the North.
Some 4,500 personnel are taking part in five days of drills in the Yellow Sea, near the disputed maritime border.
The South is making a show of strength amid continuing anger over the sinking of one of its warships in March.
Why? Is South Korea sending the message "don't fuck with us"?