[slimsag]

But, I mean, NATO must also make very similar decisions, right?

If a NATO nation gets 'attacked' by somewhat provoking a war, NATO must ultimately make some sort of decision about whether or not to jointly act (and foot the bill).

[di4na]

Yes but the treaty itself is pretty precise. You can look at it, but basically : if it is not a direct attack on the North Atlantic country sovereign soil, NATO do not have to do anything.

[dredmorbius]

NATO Article 5: Collective Defence.

http://www.nato.int/cps/en/natohq/topics_110496.htm

_Collective defence means that an attack against one Ally is considered as an attack against all Allies._

It has been invoked once. In 2001.

[BanzaiTokyo]

it is easier to determine if a country was attacked (the case of NATO) than if the petent holder is a troll (the case of anti troll alliance)