It's the first endnote in Duke's book:
Duke, Dr. D. "A Life-Changing Conversation in Moscow"
Duke Report 2002.
Maybe someone else can track down a copy of the entire 2002
Duke Report to get the full article. I wasn't able to find it.
As Wahrheitssucher wrote, Duke is reporting a conversation he had with Solzhenitsyn himself. It's not from any of Solzhenitsyn's books, but he had recently finished the second volume of
Two Hundred Years Together.
There are also relevent quotes in
that book. These are a few from one chapter.
The Bolsheviks thus appealed to the Jews from the very first hours of their takeover, offering to some executive positions, to others tasks of execution within the Soviet State apparatus. And many, many, answered the call, and immediately entered. The new power was in desperate need of executors who were faithful in every way—and there were many of them among the young secularised Jews, who thus mingled with their colleagues, Slavs and others. These were not necessarily “renegades”: there were among them some without political party affiliations, persons outside the revolution, who had hitherto remained indifferent to politics. For some, this approach was not ideological; it could be dictated only by personal interest. It was a mass phenomenon. And from that time the Jews no longer sought to settle in the forbidden countryside, they endeavoured to reach the capitals...
Trotsky himself was an incontestable internationalist, and one can believe him when he declares emphatically that he rejects for himself all belonging to Jewishness. But judging by the choices he made in his appointments, we see that the renegade Jews were closer to him than the renegade Russians.
The omnipresence of the Jews alongside the Bolsheviks had, during these terrible days and months, the most atrocious consequences. Among them is the assassination of the Imperial family, of which, today, everybody speaks, and where the Russians now exaggerate the share of the Jews, who find in this heart-wrenching thought an evil enjoyment. As it should, the most dynamic Jews (and they are many) were at the height of events and often at the command posts.
What brought all these rebels together—and, later, beyond the seas—, was a flurry of unbridled revolutionary internationalism, an impulse towards revolution, a revolution that was global and “permanent”. The rapid success of the Jews in the Bolshevik administration could not be ignored in Europe and the United States. Even worse: they were admired there! At the time of the passage from February to October, Jewish public opinion in America did not mute its sympathies for the Russian revolution.
So if someone wants to discount the authenticity of David Duke's quote, that's fine. But it's more difficult to dismiss the
many similar sentiments throughout
Two Hundred Years Together.
It's also worth noting that Duke's Solzhenitsyn quote doesn't explicitly mention Jews. And some of theme of
Two Hundred Years Together is echoed in
The Jewish century, a
book written by a Jew that won awards. Kevin MacDonald wrote an article reviewing Slezkine's book and expanding on it: "Stalin's Willing Executioners."