Is Putin Prioritizing Regime Survival Over Fighting Terrorism?

Responsibility for the March 22 terrorist attack at the Crocus City concert hall has been claimed by the Afghanistan-based Islamic State Khorasan (ISIS-K), and most of the suspects are migrants from Tajikistan. Yet Russian authorities remain steadfast in their insistence that Ukraine and "Western forces" orchestrated the indiscriminate murder of over 140 people. What does this fixation on Ukraine signify for Russia’s regime stability? Is there genuine conviction within Putin’s inner circle that Ukraine masterminded the attack? And what real threats does Russia face from radicalization in Central Asia?