Russian military build-ups

From March to April 2021, Russia commenced a major military build-up near areas that border Ukraine. A second phase of troop expansion took place from October 2021 to February 2022. During the second build-up, Russia issued demands to the U.S. and NATO for what it referred to as "security guarantees". Russia advanced two draft treaties that included a legally binding promise that Ukraine would not join NATO, as well as a reduction in NATO troops and military hardware stationed in Eastern Europe. In addition, Russia threatened an unspecified military response if NATO continued to follow an "aggressive line".

Source: https://en.wikipedia.org/