Say in a future war, a renewed Korean conflict perhaps, the North Koreans attack U.S. (and ROK) troops with several hundred chemical weapons (nerve gas).
How would the U.S. respond? I know the U.S. claims that it would respond with nuclear weapons to such an attack as chemical weapons are considered WMDs, but does anyone really think the U.S. is going to start hitting the North Koreans with a bunch of 10-50 kiloton warheads just because of a chemical attack?
Not to mention the South Koreans and Japanese would probably object to any first use of nuclear weapons by the U.S. regardless of the circumstances.
so short of nuclear weapons, how does the U.S. respond to a chemical attack?