Intensifying Russian pressure on Belarus is degrading Belarusian President Alexander Lukashenko’s maneuver room to avoid making concessions to the Kremlin, says the Institute for the Study of War (ISW).

Russian President Vladimir Putin’s long game to reestablish suzerainty over Belarus is reportedly making progress separate and apart from Putin’s efforts to get Belarus more actively involved in his invasion of Ukraine.

According to ISW, Lukashenko confirmed that Russia “gave” Belarus an unspecified number of S-400 air defense systems during his meeting with Putin in Minsk on December 19, confirming ISW’s 2021 forecast that Russian-made S-400 systems would begin operating in Belarus.

Lukashenko had previously rejected S-400 systems operating in Belarus in 2020.

ISW considers that Lukashenko is likely delaying acceding to Putin’s larger demands - such as committing Belarusian forces to join the invasion against Ukraine - by making smaller concessions that he has stonewalled for years. 

Meanwhile, media reports, citing Ukrainian government officials, say Ukraine is tightening up the defense of its border with Belarus over fears that Russia may be preparing a fresh attack.

Belarus shares a border with Russia as well as Ukraine.

Russia's defense ministry announced that its troops stationed in Belarus would conduct joint military exercises with Belarus.

The BBC reports that reacting to this and Putin’s visit to Belarus Ukrainian Deputy Defense Minister Yevhen Yenin confirmed: “We are building up our defense lines all across the border with Russia and with Belarus.”

While Belarus has not become involved in the war directly, it allowed Russian troops to use its territory to launch the so-called “special military operation” in Ukraine on February 24.