Russia launches the active phase of vast military exercises in Belarus on Thursday, a display of strength that shows how Moscow’s tightening grip on Minsk has given it enhanced capabilities in its standoff with the West over Ukraine.

The joint Allied Resolve drills that Nato has described as Russia’s biggest deployment to ex-Soviet Belarus since the Cold War run until February 20 and are part of a Russian troop buildup near Ukraine that has stirred fears of a looming invasion.

Russia, which denies any invasion plans, has not disclosed how many troops will be involved. Many of the troops have been deployed from thousands of miles away in Russia’s Eastern Military District in the far east.

Nato secretary-general Jens Stoltenberg said last week that Russia was expected to have 30,000 troops as well as Spetsnaz special operations forces, SU-35 fighter jets, S-400 air defence systems and nuclear-capable Iskander missiles.

In military terms, the deployments create a new front for Ukraine to worry about and stretch Kiev’s forces thinner around its long defensive perimeter, said Neil Melvin, director of International Security Studies at the RUSI think-tank in London.

For years, Belarusian leader Alexander Lukashenko, a wily political operator in power since 1994, played off East against West for political gain and resisted the idea of hosting a permanent Russian military base.

But since Russian President Vladimir Putin shored him up with political and economic support to help him weather huge Opposition protests in 2020 he has shed much of that veneer of autonomy, analysts said.

“I think he finally decided that in order to stay in power he should rely on his strategic alliance with Moscow and of course these joint military exercises are yet another kind of manifestation of this new closeness,” said Andrey Kortunov, head of the Russian International Affairs Council which is close to the Foreign Ministry in Moscow.

“Now he has full backing from Putin in exchange for his loyalty. Apparently both sides are happy with this deal, at least for the time being,” he said.

In recent months, Lukashenko has publicly offered to host Russian nuclear missiles in Belarus. Moscow and Minsk have agreed a joint military doctrine for their “union state” integration project.

Last year the two countries opened a joint training centre in Grodno in western Belarus. “This is basic code for a permanent presence,” said Mathieu Boulegue, a research fellow at London’s Chatham House think-tank.