This week Russia’s Foreign Minister Sergei Lavrov issued a warning to the West: “They should understand – they are joking about our red lines here. They shouldn’t joke about our red lines.” Coming from a nuclear power, that sounds like Russia would be prepared to use a nuclear weapon.Right from the beginning of Russia’s war its President Putin has warned the West not to defy his ambitions in Ukraine. But Washington and its allies increased military aid to Ukraine.Also this week, the Kremlin said it’s revising its nuclear doctrine. It’s believed that could mean a lowering of the threshold for the use of nuclear weapons.And a new Russian weapon has grabbed the attention of the West. It’s not a nuclear warhead, but a new cruise missile that’s powered by a small nuclear reactor. It called the Burevestnik in Russia, but the United States has given it the name “Skyfall.” US researchers believe they have now found the first launch site for the experimental missile. It’s believed to be located at a nuclear warhead storage facility, nearly 500 kilometers north of Moscow. President Putin says its nuclear propulsion system gives the missile an almost unlimited range and means it can evade missile defenses. Western analysts say the technology could pose more of a threat to Russian than its adversaries.00:00 Russia’s nuclear ambitions01:48 DW speaks with Decker Eveleth, associate research analyst at CNA, the Center for Naval Analyses