let me try this again. USA claims they were attaced from abroad. They also claim this attack to be an act of war. After the USA handed over the evidence aiming bin Ladens network, Nato accepted the US claim that the attack was an act of war.
When Nato decided to accept US claims, means that when one membering NAto country is attacked ALL the membering countries are attacked. This is the article 5.(one for all, all for one)
WAR is not decleared yet but TECHNICALLY we are at war according to the Nato resolution.
I quote the Norwegian minister of foreign affairs
"NATO has accepted the proof that the terrorist attack in NYC and W.DC is looked at as an foreign attack, and this means it is an attack on all membering countries"
But I think I do remember reading that the US itself has decided not to invoke article 5.
USA has taken it to NATO for support. NATO agreed to the American claim. Artical 5 is then automatically invoked.