Joint military exercises by Russia & Belarus “have included S-400 air defense systems positioned very close to the Polish border...
Positioning the S-400s there is part of a broader move by the Russians to complicate the airspace in a way that would deter Western intervention.” https://twitter.com/nakashimae/status/1493768533368442887

“In addition, the missiles that military analysts say Russia has placed in the Russian enclave of Kaliningrad, Belarus, in Russian territory…&in the Black Sea, when combined with the S-400s, would make a flight into Ukraine by U.S. or allied aircraft incredibly risky…

“Russia underscored its naval powers & regular proximity to U.S. & NATO vessels with a massive exercise Tuesday in the Mediterranean. Russian DM Shoigu observed the drills, which state news agency Tass said involved more than 15 combat ships

“Russia also has moved a fleet of naval vessels into the Black Sea, including Ropucha-class landing ships designed to invade territory through beach landings. A Russian kilo-class submarine…was spotted this week passing through the Bosporus into the Black Sea.”

“It’s a signal, said retired Adm. James G. Foggo III, former commander of U.S. Naval Forces Europe-Africa, ‘it will be a combined land, air and sea campaign.’”