No nuclear nation has done this as well as one might wish, and Japan's failings may well become more evident.

as one might wish为比较分句，分句省略了成分，补全后的分句是：

as one might wish it would do it (  ).

第一个it指代nuclear country, 第二个it指代this。（ ）表示比较分句的空位（gap). 如果将as分析为连词不作成分，从句就缺少方式状语，其位置由空位表示。如果将as分析为比较副词，则as占据了空位的位置，为分句的方式状语。