Ever since its full-scale invasion of Ukraine, experts say Russia has stepped up its hybrid war on Western Europe. Attacks on critical infrastructure or using drones to shutdown airports are meant to undermine support for Ukraine.

As losses mount, the pace of Russia's advance has at times been slower than the Battle of the Somme during World War I, a report says.

High-level military communication was suspended in late 2021, as tension between Moscow and Washington rose ahead of the full-scale Russian invasion of Ukraine in February 2022.