NATO has invoked Article Five of its charter that paves the way for war, it paves the way for a retaliatory response by the USA against those responsible for yesterdays terrorist attacks.
Article Five states that any armed attack against one of its members is considered an attack against them all.
NATO member states have agreed to aid the United States in any response it may make to the attacks.
The USA will have to ask for specific kinds of support, but by invoking Article Five provides an fast-track clearance for use of airspace by the allies and makes other kinds of assistance available, such as military and intelligence sharing.
The USA Congress is making way for money and resources to rescue survivors, help victims and their families, and for steps to improve U.S. security and defense.