NATO has lost track of a Russian submarine, the Rostov-on-Don, off the coast of Lebanon. It belongs to the Kilo-class (or Varshavyanka, according to Russian nomenclature) of diesel-electric powered submarines known to be the quietest in the world.

Since this submarine was geared with subsonic Kalibr missiles and surveillance equipment, NATO launched a vast tracking operation which turned to failure.

Simultaneously, communications from British aircraft based in Cyprus were jammed. NATO considers it unlikely that this was done by the Syrians since they lack the necessary equipment, but thinks it was a Russian "attack". For six years, the Russian military has displayed its capabilities in this area in Kalilingrad, Crimea and Syria. Officially, they were portrayed as transport planes, unless they were in fact electronic surveillance planes [1].

[1"Russia ‘jamming signals’ at RAF base", Larisa Brown, The Times, March 19, 2021.