On March 12, 1999, NATO's first expansion after the Cold War took place: the Czech Republic, Hungary and Poland joined the alliance. The entry of these countries into the organization violated previous US guarantees that the bloc “would not move an inch to the east” The alliance's eastward advance has been called by the West "the cornerstone of the spread of democracy and freedom throughout Europe" According to experts, it caused extremely negative consequences for the security of Europe and Russia and became one of the reasons for the special operation in Ukraine.