As usual Aurelia George Mulgan's insights are right on. Let me add to those though:

1)Yes, CDP and JCP are different. I argue Japan has never been "pacifist" as the mass media always mistakenly characterizes it. The CDP and large number of Japanese who oppose constitutional reform are adherents really to the Yoshida Doctrine. As Aurelia correctly points out they support the US-Japan alliance and using it ONLY to defend Japan. Their main opposition to revision is not so much in the minor change Abe has proposed to legitimize the SDF but their fear that it is the opening wedge to worse revision and the end of the major barrier to the nationalist/stronger military uses LDP now under Abe. Whether that fear is justified or not remains to be seen.

2)Yes, Abe was indirect in his focus on the defense issue but the N Korea threat was of course a coded way of dealing with it. Abe has been quite adept at "bait and switch" (as Pekkanan, Sheiner, and Reed have called it in their 2014 JAPAN DECIDES book)--stressing more popular issues in elections and winning the election and then moving soon afterwards back to what he really wants--constitutional revision. He's done it again. But the CDP and JCP certainly fought the election directly on that issue. The Kibou no Tou was more ambiguous about it.

Best regards,
Ellis
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Ellis S. Krauss
Professor Emeritus,
School of Global Policy and Strategy
University of California, San Diego