Shortly after unveiling a new uranium enrichment facility, North Korea has shelled a disputed island held by the Republic of Korea. A score of South Koreans reportedly were killed or wounded.

These two steps underscore the North’s reputation for recklessness. Unfortunately, there is no easy solution: serious military retaliation risks full-scale war, while intensified sanctions will have no impact without China’s support.

Instead, the U.S. should join with the ROK in an intensive diplomatic offensive in Beijing. So far China has assumed that the Korean status quo is to its advantage. However, Washington and Seoul should point out that Beijing has much to lose if things go badly in North Korea.

The North is about to embark on a potentially uncertain leadership transition. North Koreans remain impoverished; indeed, malnutrition reportedly is spreading. With the regime apparently determined to press ahead with its nuclear program while committing regular acts of war against the South, the entire peninsula could go up in flames. China would be burned, along with the rest of North Korea’s neighbors.

The U.S. also should inform Beijing that Washington might choose not to remain in the middle if the North continues its nuclear program. Given the choice of forever guaranteeing South Korean and Japanese security against an irresponsible North Korea, or allowing those nations to decide on their own defense, including possible acquisition of nuclear weapons, the U.S. would seriously consider the latter. Then China would have to deal with the consequences.

Beijing’s best option would be to join with the U.S. and South Korea in offering a package deal for denuclearization, backed by effective sanctions, meaning the cut-off of Chinese food and energy assistance. Otherwise, Beijing might find itself sharing in a future North Korean nightmare.