Jünger has long been a controversial character. His inter-World War writings have been interpreted as supportive of the need for a strong, Nazi-like party to lead Germany while his own experience showed a marked ambivalence toward the Nazis. As the article points out, "Jünger's belief system was an idiosyncratic mysticism that drew equally from science and religion; by temperament he was essentially a German romantic, for whom intense personal experience led to an understanding of the fundamental unity of nature." Since that doesn't seem to support any historical political party, no wonder it's difficult to pin him down.
Michael Lewis' review notes the lack of editorial notes, its poor translation at times, and the omission of Jünger's preface to his original release of the diaries. Even so, it's an important addition to investigating the events of World War II from a German viewpoint. As Lewis notes at the end of the review:
There is still ample material here to debate the moral choices made—and evaded— by Jünger, and to ponder [Jean] Cocteau's final verdict, who liked Jünger but whose aloofness troubled him: "Some people had dirty hands, some had clean hands, but Jünger had no hands."
Related: My notes on On the Marble Cliffs can be found here.
Update: Please see Simon Friedrich's note in the Comment section. If you you are interested in finding out more about Jünger and his writings, see his blog at ernst-juenger.org. Simon's review of the diary can be found here, which also has links to additional reviews, including one by Michael Dirda.
Note: I find that sometimes the full version of the review comes up while a truncated version loads at other times. If you get the short version leading to a paywall, try again in a little bit.
Additional Note: I apologize for the extended silence. There is a lot going on, most of it good, but I don't want to say much about it at this point. Posts will be scattershot in timing and content for a few more months.