US warns Russia for planned terror attack in Moscow
Russian government and Putin specific either ignore it for the reason the west is fooling them because would fit narrative for the war in Ukraine. Or
Russian government is just incompetent to do anything with that information. Or they know and deliberately don't do anything with it to link it to Ukraine (even though the perpetrators are IS). Since this was also done in 1999 to blame the Chechnyans, it would fit the profile.
Either way it will be Soviet style lying. The incompetence will be wiped under the rug. The deliberate holding back information and not adequate precautions will not be easily to be proven, yet it creates the narrative for the mobilisation. Fear is Russia's weapon of mass destruction, the lies are the instruments to fire those weapons.
“Every lie we tell incurs a debt to the truth. Sooner or later, that debt is paid.”