SO FAR, not so good for Abenomics, the ambitious program for reviving Japan’s stagnant economy introduced by Shinzo Abe upon his election as prime minister three years ago. Mr. Abe promised to fire “three arrows”: fiscal stimulus, monetary easing and structural reforms. He has delivered most dramatically in the monetary area, where the Bank of Japan has tried radical anti-deflation measures, including, most recently, negative interest rates on commercial bank deposits at the central bank. Yet in view of the underwhelming results — including another three months of negative growth at the end of 2015 — Japanese are worried and the prime minister’s approval ratings are falling. Meanwhile, China and North Korea agitate militarily nearby.