Ash Carter: “We have an obligation to do that, and we've made that clear, right from the beginning of the train-and-equip program.”

China has and shares important responsibility for this development and has an important responsibility to reverse it.

The international community, United Nations Security Council and especially the other six-party powers must hold North Korea accountable for this latest act and heighten the pressure on North Korea.

"Up-or-out" isn't broken--in fact, it's an essential and highly successful system--but it's also not perfect.

I can't support, and won't support, is anything that moves towards instability.