Swedish intelligence services refused to cooperate with their French and Belgian counterparts which resulted in the Paris and Brussels attacks.
Summary
The former president of France Nicolas Sarkozy stated that the world failed to unite against Daesh and western countries made a dramatic error when they spoiled relations with Russia, because without this country establishing peace in Syria will be impossible.
Disproof
There is no sign of Nicolas Sarkozy's statement outside pro-Kremlin media.