The United Nations, with the support of the U.S. and China, has responded appropriately to North Korea's brazen nuclear test and rocket launch with the passing of toughened sanctions. The U.S. and South Korea have strengthened military capacity at the Demilitarized Zone between the two Koreas and China has reportedly bolstered its troops along the Yalu River that forms the North's northern border.
The prudent initial response has been to unleash the dogs of sanctions to convey condemnation to Kim Jong Un and his military so they do not inaccurately conclude the world is indifferent to their actions and repeat them.