Across Russia, 40 million civilians and military personnel just finished up emergency drills aimed at preparing the general population for nuclear or chemical-weapons attacks, The Wall Street Journal's Thomas Grove reports.

Video shows Russian civilians practicing along with officials and workers in hazardous-material protective suits.

But as troubling as the largest civil defense drills since the height of the Cold War have been, the steps Russia has taken to improve its offensive nuclear capabilities likely overshadow them.

Since the breakdown of US-Russia talks on the fate of Syria, Russia has pulled out of a nuclear-nonproliferation agreement with the US, citing "unfriendly acts" by America. It has moved nuclear-capable missiles to its European enclave of Kaliningrad, and threatened "asymmetrical" and "painful" actions against the US should it decide to impose sanctions on Russia over Syria.

Russian Yars RS-24 intercontinental ballistic-missile system during a parade to mark the end of World War II at Red Square in Moscow. Thomson Reuters

Additionally, Russia's state-run media has been ratcheting up anti-American rhetoric.

Lev Gudkov, head of the Russian polling group Levada-Center, told The Journal that in Russia "most people believe that the Third World War has begun, but right now we are still in the cold phase of the war, which may or may not turn into a hot war."

In Syria and the Ukraine, Russia has turned away from diplomacy and toward military solutions to standoffs with the West. Russia's recent installation of another missile defense battery in Syria gives the US very few options to intervene without risking serious casualties.

Further, Russia designed its nuclear weapons arsenal as absolute doomsday devices that rain up to 10 high-yield nuclear warheads down on targets at Mach 23 in a salvo that the US can't possibly hope to intercept.

Russia Emergency Situations Ministry workers wearing biohazard suits. Ministry of Emergency Situations press service via AP

The US has long relied on the doctrine of "mutually assured destruction" — that is, having a spread-out, autonomous, and effective nuclear arsenal that would return fire should another nuclear power attack — with the intent of deterring any nuclear attacks. But sources told The Journal that Moscow is now taking steps to ensure that 100% of its population would be sheltered from such an attack.

Far from matching Russia's aggressive nuclear posturing, the US has had its attentions elsewhere. The US's long-range bomber aircraft, the most visible deterrent of a nuclear arsenal, have mainly been stationed in the Pacific in response to North Korea's nuclear aggression.