a. BOJ were under pressure, so they couldn't do anything.
b. MOF was busy, and they had no other choice.
c. Politicians had other interests, so they weren't available.
d. So, there was nothing that could have been done (or could be done in the future) to avoid (or get out of) the Japanese recession.
Now, this is meaningless. Of course everybody has some excuses if you ask them. I guess the Nazis had their reason for their gas chambers, too, and most of them "couldn't do anything." Stalin would have said he had no other choice. But should we just say "oh well" and let it go? I don't think so. What has happend, happened, but one point of thinking about history is to figure out the options that might have been taken to prepare for future situations. This book doesn't do that, it simply justifies the status quo.
This often happens when you get to close to the subject and sympathize too much.
His attitude is apparent in his arguments about the inflation targetting argument proposed by Krugman (and almost every other economist right and left). He discribes that BOJ can't do it, the current law doesn't allow it. Well, who said BOJ has to do it alone? But Grimes never even thinks about any possiblity of changing the present, or the possible merits that it would bring IF it happened.
That's the limit of this book. Three stars for the considerable research effort, but this is a result of much perspiration and no inspiration.
Oh, and next time, get a better caligrapher for the cover.