The new NATO policy, announced on June 14th, states that a cyber-attack against any NATO country qualifies automatically as constituting “war” against all NATO countries, just like any traditional attack. Such a claim and proof of the target-nation’s guilt is a subjective decision by the President of the US.
This would be a political decision for the U.S. President to make; one which can be made only by the U.S. President, and which only he or she possesses the legal authority to make. NATO made clear that any NATO-member nation’s leader who can claim that his or her nation has been ‘attacked’ by Russia, possesses the power to initiate a NATO war against Russia if the US President concurs.
So, for instance, Any US President might arbitrarily decide that the U.S. was invaded by Russia when former U.S. Secretary of State Hillary Clinton’s State Department emails were copied by someone in Russia and require all NATO nations to immediately join an actual, shooting war with Russia…or China…or, really, any country in the world.