What are Iran and Russia's mounting hybrid attacks on Europe?

What happened: MI5 chief Sir Ken McCallum said the U.K. has entered a new era of national security, with Russia the top state threat and Iran expanding hybrid campaigns. He cited over 50 arrests in the U.K. in the last year. Key numbers: More than 50 arrests in the U.K. over the last year. Incidents listed span March 9 to Oct. 2. Why it matters: McCallum said Russia is escalating hybrid warfare while staying below the NATO Article 5 threshold, and that much of the aggression has targeted British Jewish communities and military sites.

MI5 chief Sir Ken McCallum said the U.K. has entered a new era of national security, with Russia the top state threat and Iran expanding hybrid campaigns. He cited over 50 arrests in the U.K. in the last year.

McCallum said Russia is escalating hybrid warfare while staying below the NATO Article 5 threshold, and that much of the aggression has targeted British Jewish communities and military sites.