wesley clark, commander-in-chief. nato forces in europe. let's listen. this a clear war crime. ukrainians would not do this, no matter how angry they are with russia and no matter how this terrorist attack demonstrates the horrors of war to muscovites who are favorable to putin. there is no doubt that the ukrainians are working against the russians. there is an attack in belgorod. ukrainian agents are infiltrating russia and drones are flying in. i think that this whole situation has led to some imbalance in the russian system. such a statement, especially considering that this month the us embassy has already issued a public warning about extremists planning to carry out a terrorist attack. the term extremists typically refers to these fanatical islamist groups, the igelka, which are believed to be possibly responsible for the attack. the russians have long been believed to have brutally suppressed muslims in syria and afghanistan, as well as the caucasus. therefore, i consider it very plausible that it was islamic militants who carried out the attack. and here's mike mcfaul.