Lavrov had said it would be a short war if Europe attacks, suggesting they will use nuclear weapons immediately. Russia knows it cannot win a conventional war with Europe.
They don't need a war with Europe for conscription, just to declare war on Ukraine instead of a Special Military Operation. There is pressure on Putin to do this to finish the war quickly, but he is resisting.
Lavrov is a known liar: you can tell by the fact that he's moving his lips. That's kind of his job, really: lying.