Quotes from Jumper: “We are not at war with anyone, and I'm curious why this Act of War keeps being brought up as a catch all, it simply is not true.”
“Again the Canadian Government, to my knowledge, has not declared war on anyone”
http://www.un.org/aboutun/charter/
Article 2
All Members shall give the United Nations every assistance in any action it takes in accordance with the present Charter, and shall refrain from giving assistance to any state against which the United Nations is taking preventive or enforcement action.
there is of course much more, however...
I don't see it as Canada declaring war. A NATO member had been attacked by a group of people who tend to make their home a certain country. Those people are also harboured by the closest thing to a federal government that country has. If one nation of NATO is attacked, all the other members must contribute what they can to the efforts that are taking place. I dont truly think Canada had to declare war, as we are part of NATO, NATO decides that for us, more or less.
The US was attacked by an identifiable group who made camp in A-stan. The Taliban harboured this group. The US wanted to take action, eliminate the threat and remove the Taliban from power. As they did this, we were required, as an able nation to assist in whatever way we could.
Even if it is not a "war", that does not mean anything. If you apply the word war to something, the rules change. Like genocide, if a nation aknowledges genocide, they are obligated to do something about it, so they tend to use the words "Ethnic Cleansing". How do you think they helped themselves stay out of Darfur for so long?