When Islamic State militants posted a video over the weekend showing the grisly killing of a Japanese journalist, Prime Minister Shinzo Abe reacted with outrage, promising “to make the terrorists pay the price.”Such vows of retribution may be common in the West when leaders face extremist violence, but they have been unheard of in confrontation-averse Japan — until now.. 

It wasn't a reassuring moment. Speaking at the World Economic Forum in Davos, Switzerland on Wednesday, Shinzo Abe, the Japanese prime minister, compared recent tensions between China and Japan to the rivalry between the British and German empires at the start of the 20th century.