NATO says the internet is now a war zone – what does that mean?

On 14 June, news broke that someone had hacked into computers at the US Democratic National Committee, exposing opposition research on Republican presidential candidate Donald Trump, as well as a trove of chat logs and emails. Some blamed Russia – although as ever details are unclear. The same day, NATO announced that it was designating cyberspace as an "operational domain" for war alongside land, sea and air. Reports of one country attacking the computer systems of another – like this week's hack on the Democrats, last year's Chinese breach of the US Office of Personnel Management, or North Korea's attack on Sony in 2014 – have become common. The details of hacks may differ, but the story is a familiar one. Does NATO's announcement change anything?