it was a formal treaty not an executive agreement like say P5+1 agreement was just an executive agreement
A formal treaty ratified by the Senate? I can find no such treaty:
"Russia was a participant in these new security arrangements, and was keen to clarify that Nato enlargement was not a security threat to Russia. The then president of Russia, Boris Yeltsin, wrote in a September 1993 letter to the then US president, Bill Clinton: “Any possible integration of east European countries into Nato will not automatically lead to the alliance somehow turning against Russia.” So it was being clearly signalled that Russia did not object to the direction Europe’s new security architecture was following. The three Visegrad countries were duly invited to join Nato at the 1997 Madrid Summit, joining in 1999. Slovakia was forced to wait until 2004."