Your assumption that the FSb has no reason to undertake a false flag attack in Russia is incorrect.
FSB has every reason to undertake another false flag attack in Russia to gin up more local support for Putins miserably failing invasion of Ukraine. Opinion polls show declining support among Russians for Putins failed war, these attacks help solidify weakening support, especially now Putin needs to send hundreds of thousands more Russians to the slaughter.
There is amole motivation evident to explain a false flag FSB attack.
