The Diet last week approved the trade deal struck by Prime Minister Shinzo Abe and U.S. President Donald Trump. An agreement was inevitable given Trump's trade fixation, his insistence that only he can negotiate a deal that would benefit the United States, and Abe's need to maintain good relations with Washington. The result is a limited, seemingly interim deal, that leaves both sides wanting more.

One of the few constants in Trump's worldview is that the U.S. has been exploited by its trade partners, and he has long seen Japan as a grievous offender. It was taken as given that he would act on that frustration when he became president and soon after taking office he began talking about a trade agreement with Tokyo.

The two leaders agreed to begin trade talks a little over a year ago, and negotiators moved rapidly forward, reaching agreement in October. The Diet quickly approved the deal. The U.S. needs no legislative approval, and the agreement will go into effect on Jan. 1.