Russia could attack a Nato country within the next five years, the Western military alliance's chief has said in a stark new warning, BBC reported. 

"Russia is already escalating its covert campaign against our societies," Mark Rutte said in a speech in Germany. "We must be prepared for the scale of war our grandparents or great-grandparents endured."

He echoed similar statements about Russia's intentions made by Western intelligence agencies, which Moscow dismisses as hysteria, according to BBC.