I suppose that when this story was written, Japan must have seen like quite a threat to the Americans. Because that's how Japan comes across; an unstoppable economic and cultural juggernaut that threatens to colonize the U.S.
The plot of this story seems at times pieced together to serve this concept, and while many of the traits of the Japanese depicted in the story ring true, the rest of it just looks like paranoid crap.
The U.S. needed no foreign power to ruin its economy and buy up its resources. The powers that be in the U.S. saw to that all on their lonesome.
Other than that, I didn't get the sense that the main character was acting true to form. It seemed quite difficult to believe that a lone policeman would keep finding reasons to zoom back and forth across California, moving through circles inhabited by beautiful scientists and scheming politicians with such ease and without so much as having to fill in a timesheet. I mean, how many L.A. cops find themselves at daytime parties in the hills?
With little story-wise to support the out-of-date politics, there is little to recommend this story.