Hidden among hills, mostly in tunnels, hundreds of North Korean heavy artillery pieces stand ready to rain thousands of shells a minute onto Seoul. For decades, the big guns have been the biggest threat that South Korea has had to face. More recently a new one has become more prominent in the South's strategic calculations: an uncertain number of nuclear warheads of uncertain performance and reliability, potentially fitted to ballistic missiles fired from heavily protected sites in the far north of the Korean Peninsula.

SEOUL — If the South Korean air force’s plans come to fruition, by 2030 its leading combat aircraft will be pilotless – and domestically made.

China Southern Airlines will order six Boeing 777F freighters in a move that it says is part of its development strategy. The aircraft, with a catalog value of $1.58 billion, will be delivered between 2013 and 2015, says the airline, adding that it will finance them partly with bank loans. The order, which has not been finalized, will be a new deal, not part of a previously announced bulk contract with the Chinese government, says a Boeing official.