Whether by error or design, Mrs Merkel gave him an 18th-century map that excluded Tibet, Xinjiang, Mongolia and Manchuria from China's domains; it also seemed to exclude the islands of Taiwan and Hainan.
She was Chinese, a waiter's daughter affectionately known as Jade Lute, but had been educated at a Japanese school in Manchuria.
One, the traditionalist, is the nationalist grandson of Nobusuke Kishi, who oversaw the development of Japanese-occupied Manchuria in the 1930s, who was imprisoned as a suspected Class A war criminal, and who later served as a notable conservative post-war prime minister.
At the time, the Goguryeo kingdom ruled central and northern Korea and held territory extending into parts of Manchuria and Siberia.
Most of the unit's activities took place in occupied Manchuria, in north-east China, where the victims of its ghastly experiments were Chinese, Koreans and Russians.
Upset that Jewish émigrés in southern Manchuria were being taken for Germans, the consul there proposed stamping the covers of their passports with a red J, a suggestion that Heinrich Himmler, the Gestapo chief, took up.
But for many Chinese, hostilities started in 1931 with Japan's invasion of Manchuria, and for South Korea 100 years ago with its annexation by Japan.Uncle Sam's umbrellaJapan was able to turn its back on Asia for most of the post-war period because of a strong security alliance with America that has now been going for 50 years.
Pork- and vegetable-filled gyoza dumplings, served up in massive quantities by Japanese housewives, are essentially Chinese jiaozi, popularised in Japan during its occupation of Manchuria from 1931.
And yet he has already stirred up ill will with China and South Korea by asking whether imperial Japan (for which his grandfather helped run occupied Manchuria) really was an aggressor, and by allowing his deputy to visit the Yasukuni shrine, where high-ranking war criminals are honoured among Japan's war dead.
During the 1930s he ran industrial policy in the puppet-state of Manchuria.
When Korea was a Japanese colony, Park Chung-hee joined the Manchukuo Imperial Army, and fought in Manchuria in the 1940s.
