Explainer - U.S. government hack: espionage or act of war?

A man types into a keyboard during the Def Con hacker convention in Las Vegas, Nevada, U.S. on July 29, 2017. REUTERS/Steve Marcus/Files

(Reuters) - The suspected Russian hack of U.S. government agencies has led to heated rhetoric from lawmakers, with U.S. Senator Dick Durbin calling it "virtually a declaration of war" and U.S. Senator Marco Rubio saying that "America must retaliate, and not just with sanctions."

But cybersecurity and legal experts said the hack would not be considered an act of war under international law and will likely go down in history as an act of espionage.