The North Atlantic Trade Organization (NATO) has officially announced that "cyber" will become an official battleground for its members, which means that cyber-attacks on one country will trigger a collective military response from the entire alliance.

The announcement comes from NATO Secretary General Jens Stoltenberg, who made this statement while speaking at a press conference in Brussels, Belgium, on Tuesday, June 14, Bild reports.

Official warfare domains are now air, sea, land, and cyber

NATO's Article 5 dictates that any attack on one of its members is to be considered an attack on all, and the response should come from all. Until now, this has meant military assaults via air, sea, and land.

In the past years, cyber-attacks have become the norm, creating an alternative battleground where there are no limits and alliances.

Iranian, Chinese, and Russian hackers have been tearing the US and other Western powers apart, and in most cases, countries just issued "official accusations," and nothing more.

Will this deter cyber-espionage groups?

Raising cyber to an official rank of warfare domain will bring with it all the legal and political complications that come when putting boots on the ground in another country or launching missiles across a border.

Most NATO members have already recognized cyber as an official battleground and have set up so-called hacking divisions in their armies, with the US leading the way. The most recent US divisions that did so this year are the US Marines and the US Navy.

While attribution to cyber-attacks may remain a tricky and complicated affair, such attacks against NATO members happened in the past.

One such cyber-espionage group is Fancy Bear, also known as Sofacy, APT28, Sednit, Pawn Storm, or Strontium, which attacked NATO military bases and officials in April 2015. Security experts believe that Russia's military intelligence service GRU may be behind this group.