In May of last year, the US Government published its International Strategy for Cyberspace. The publication made some waves in the international community because in this document the US stated that military reprisals to cyber attacks were now officially on the table.
More specifically, the US government stated that it ‘encouraged responsible behavior and oppose those who would seek to disrupt networks and systems, dissuading and deterring malicious actors and reserving the right to defend these national security and vital national assets as necessary and appropriate’ [emphasis mine].