His 2013 book, Tyranny of the Weak, won the John K. Fairbank Prize, but he returned it in 2017 after the American Historical Association asked him to account for issues with the citations, including plagiarism and source fabrication.
[3] He has published articles in peer-reviewed journals on such subjects as Kim Il Sung's Manchurian guerrilla heritage,[4] the "cultural Cold War" in Korea,[5] and assessments of North Korean studies as a whole.
The book received positive reviews, particularly because it appeared to draw from so many foreign archives and materials in multiple languages including Russian, Chinese, German, and Korean.
[10] Beginning in September 2016, the book was severely criticized by a number of North Korea scholars (Andrei Lankov, Balázs Szalontai, Brian Myers, Fyodor Tertitskiy and others) for deceptive scholarship.
"[21] Columbia University made no statement at this time, but did announce on June 1 that Armstrong had been awarded a 2017 President's Global Innovation Fund Grant for work with Joseph Terwilliger on exchanges with North Korean physicians.
The new text contained few changes to the prose, but did feature changes to dozens of footnotes now citing Szalontai's Kim Il Sung in the Khrushchev Era rather than archival documents.
It also included two new sentences from Armstrong in the front matter of the text: "I would like to add a special note of thanks to Dr. Balázs Szalontai, whose pioneering research was insufficiently acknowledged in the prior printing of this book and who pointed out to me numerous attribution errors in chapters 2 and 3.
[30] In February 2020, Armstrong's 2005 article: "'Fraternal Socialism': The International Reconstruction of North Korea, 1953–62", published in the journal Cold War History, was retracted for plagiarism from Szalontai's book.
[31][32] On September 10, 2019, Columbia University released a letter to faculty explaining that it had concluded a multi-part formal investigation of Armstrong's research conduct and determined that he had committed plagiarism.
According to documents obtained by journalists Khadija Hussein and Karen Xia, Columbia's investigation concluded in January 2019 and its scope extended back to Armstrong's tenure file submitted in 2003.