That hit one of China's most sensitive red lines, prompting the Foreign Ministry to issue a statement saying that the "Diaoyu Island and its affiliated islets have been Chinese territory since ancient times ... China's resolve to safeguard sovereignty over the islands is steadfast."
So, the umpteenth efforts at the Sino-Japanese rapprochement are now back at square zero.
And here is how that looks: According to the press release following the Chinese and Japanese foreign ministers' meeting on Jan. 28, "China and Japan should work together to build the East China Sea into the sea of peace, cooperation and friendship." To make sure that happens, they announced a conflict management device in the form of an "air and maritime contact mechanism."
Fundamentally, that sounds much like the Zhou-Tanaka 1972 agreement to shelve the territorial dispute. It also reminds one of comments made by China's paramount leader Deng Xiaoping, during his 1978 press conference in Tokyo, implying that was a wise decision.
South Korea is another example of a strong economic relationship with China caught up in an acutely dangerous security issue with the nuclear-armed North Korea.
Based on the full-year data for 2016, South Korea reported that China took $124.4 billion of its exports. That is 25 percent of South Korea's total sales abroad and a tenth of its economy. The U.S. came in as a distant second, buying $66.7 billion of South Korean exports, or 13 percent of the total.
Two key issues are interfering with trade and investment flows between China and South Korea. Beijing is objecting to military installations in South Korea that it considers threats to security. The second problem is South Korea's rejection of China's proposal to accept a suspension of military exercises with the U.S. (that are simulating an invasion of North Korea) in exchange for North's suspension of nuclear and ballistic missile tests. Such suspensions are seen by China as the only possibility of bringing Pyongyang to the negotiating table.
At the moment, the two Koreas are talking and preparing their joint participation at Winter Olympic Games in PyeongChang, South Korea. But, sadly, the dialogue will give way to renewed hostilities as soon as military exercises resume after the sporting events.
Japanese news outlets reported Sunday that Abe and the U.S. Vice President Mike Pence will be insisting on those exercises when they meet in Seoul the South Korean President Moon Jae-in later this week.
That will be another serious blow to any attempt at reaching agreement with China on a peaceful resolution of the Korean crisis.