Did the Gra strongly oppose the Maskilim as he did Chassidim

In Yale Professor Eliyahu Stern's recently published book on the Vilna Gaon - inserted below - asserts that he didn't publicly oppose maskilim such as Mendelssohn. 

In contrast in Rabbi Dovid Eliach's 3 volume work on the Gra - he cites letters which clearly indicate that the Gra was active in opposing the Haskala.

Prof Etkes in his biography of the Gra cites  the previous Lubavitcher Rebbe claim that the Gra was very pleased with Mendelssohn's translation and encouraged its distribution. Etkes rejects it as baseless. Any thoughts?

Update Prof Stern's Review of R' Eliach's book:MODERN RABBINIC HISTORIOGRAPHY
AND THE LEGACY OF ELIJAH OF VILNA:A REVIEW ESSAY (Modern Judaism 24 (1 )2004

Nowhere is the modern-day significance of the GRA highlighted more than in Dov Eliach’s The Gaon: The Story of His Life and an Explanation of the Teachings of Our Teacher and Rabbi the GRA. Upon opening his work, the author informs us of his cultural biases (though, of course, never calling them such). Eliach wastes little time publicizing that his unique and groundbreaking book has been blessed by his rabbi, Chaim Kanievsky, a leading figure in Haredi circles—a man who seldom if ever gives his blessings to such books. For our purposes, this blessing is mixed. On one hand, it signals an immediate red light to the critical reader. On the other hand, it also notifies the reader just how important and relevant this book is in present-day Haredi society. [...]

In volume 2 of The Gaon the strength and uniqueness of Eliach’s work emerge. Here, he offers one of the most comprehensive overviews of the GRA’s relationship to Torah study and secular knowledge. As is the case with every subject touched on by Eliach in this 1,300-page tome, it is obvious that he read through every book, manuscript, and document (though not all are cited) relating to the GRA’s stance toward knowledge not normally identified with Torah. [...]

However, the main novelty in Eliach’s analysis is his employment of the GRA as a historical marker. Specifically, Eliach uses the GRA as a figure through which he paskens (decides the religious status) on abroad range of different issues and figures identified with modern intellectual Jewish history. A paradigmatic example of Eliach’s historiography is his analysis of Maskillim such as the Av Beit-Din of Berlin, Tzvi Hirsch Levin, and Nafatali Hertz Wesseley. The GRA had little, if any, contact with these Berlin rabbinic figures. Yet Levin’s involvement in writing the only approbation for Mendelssohn’s controversial German translation of the Bible, coupled with Levin’s close ties to many individuals in the GRA’s inner circle, compels Eliach to ask how present-day Haredi culture should perceive these Berlin Jews’ religious identity. Unlike modern historians, such as Jacob Katz, who would have sought to verify whether or not someone such as Rabbi Levin was a Mendelssohnian modern, a Rabbinic apologist, or a Traditionalist, Eliach has concerns that are different but no less descriptive. Namely, he attempts to discern whether Levin or Wesseley should be termed “friend or a foe” of the GRA’s world and, by extension, modern-day Haredi culture. In Eliach’s narrative, historical categories are replaced with subjective sociotheological modes of definition. On some levels, this shift is only semantic. What the historian labels as modern is what Eliach calls “foe,” and what Eliach calls “friend” is what the historian might call traditionalist. However, in other respects this shift marks profound differences. Whereas the intellectual center for most modern Jewish historians is Western Europe and the universe and language of Moses Mendelssohn, Eliach makes the Vilna Gaon and the language and categories of the Eastern European rabbinic elite the basis from which to understand modern Jewish intellectual history. Eliach’s privileging of an Eastern European and rabbinic historiographic paradigm offers him the material to connect modern Jewish history to present-day Haredi society. This connection champions the claim of almost every leading Haredi rabbinic figure: namely, that Haredi yeshivot and social institutions are carbon copies of those thatexisted in pre–World War II Eastern Europe.[...]

Nonetheless, Eliach’s historiographic choices come with a heavy price. His attempt to make the GRA into a general in a war against the Haskalah is historically impossible. Ironically, in describing the GRA’ s relationship to the Haskalah Eliach employs a military trope. Somehow for Eliach the GRA goes from being the frail Talmudic Sage described in volume 1—a man who speaks glowingly about a diet consisting of bread and salt—to a powerful “warrior” “fighting” against the Haskalah described in volume 2. Nonetheless, the stark structuralist lines and oppositions that Eliach draws between the GRA’s Lithuanian community and Mendelssohn’s Berlin world simply could not have existed during either of their lifetimes. It was only after the GRA’s death that a demarcation between these two communities could be seen. As Edward Breuer and others have pointed out, during the GRA’s lifetime these two communities shared a great deal of intellectual currency and did not perceive each other in a hostile manner.