Another week, another round of UN sanctions against North Korea. With it comes another demonstration of how adept Beijing is becoming at inching back and forth along the policy tightrope it has installed between Washington and Pyongyang. At the same time, muttering mounts among Chinese experts and the public as to the wisdom of tightrope walking and the availability of alternatives. To placate the United States and signal displeasure with North Korea, China voted for the latest sanctions even as it insisted on watering them down to let Kim Jong-un know that China will not let him fall.