(CNN) The latest on the Ukraine-Russia border crisis- . Quoting Blinken,

“First, Russia plans to manufacture a pretext for its attack. … We don’t know exactly the form it will take. It could be a fabricated so-called terrorist bombing inside Russia. The invented discovery of the mass grave, a staged drone strike against civilians or a fake, even a real attack using chemical weapons,” he said.

For one scenario, exploited in a previous conflict, see Russia’s Ukraine Provocation; Informed Speculation, an Apartment Bombing?