MOSCOW, June 10 -- The order came without warning inside an otherwise routine government session. Vladimir Putin turned to the assembled ministers and security officials and told them the children at Starobelsk had changed something. He did not want another school.

Speaking at a meeting with members of the Russian government on Wednesday, Putin directed the heads of the country's special services and all law enforcement agencies to immediately strengthen security across Russia's educational system, social institutions, and critical infrastructure. The wording carried the weight of a standing instruction. "I ask you to carry out the relevant work promptly," he said.

The directive, reported by TASS, was framed around a single, explicit cl...