The United States says there is increasing evidence that Russia is preparing to invade Ukraine

US officials believe that Russia is laying the groundwork for invading Ukraine. The National Security Council says Russia has deployed a group of operatives to carry out so-called “false flag operations” in eastern Ukraine. Meanwhile, a cyberattack knocked out several Ukrainian government websites on Friday. CBS News correspondent Christina Ruffini is up to date and UCLA professor of political science Daniel Treisman tells CBSN’s Lana Zak why these moves are important.