British archives revealed that, in 1993, Russian President Boris Yeltsin repeatedly hinted to his Western interlocutors that, personally, he was not opposed to the accession of Poland, the Czech Republic and Hungary to the North Atlantic Treaty Organization (NATO); statements that obviously astounded his own advisers.

Boris Yeltsin was hesitant about participating in the 1997 NATO summit in Madrid, which ultimately adopted the Founding Act outlining the terms of cooperation between the Alliance and the Russian Federation. But this text has no legally binding value; it merely served as a PR tool aimed at reconciling the public and private positions of the Russian president.

During this period, Russian Prime Minister Viktor Chernomyrdin constantly warned his interlocutors against the private position of President Boris Yeltsin, underscoring that the expansion of NATO would “explode” the European continent.

«Revealed: Boris Yeltsin privately supported NATO expansion in 1990’s», Matt Kennard, Declassified UK, March 15, 2023.