You cannot invade the mainland United States. There would be a rifle behind every blade of grass.
~ Isoroku Yamamoto
Good question. The easy answer is “with whatever it takes,” according to s. 34 of the Criminal Code of Canada:
I did a little quick research into caselaw, and could find nothing, however, where a homeowner has been found to be justified in using a gun to protect people or property. (That doesn’t mean that there are no such cases, just none I could find in ten or fifteen minutes of looking.) Most often, such cases run up against another prohibition of the Criminal Code–section 87:
But the fact that the law as written makes it very difficult to self-defend with firearms helps maintain my assertion that the reason why the gun culture is different is because Canadians do not use them in self-defense. Certainly, Nunavut Boy, who admits he is a gun-owning Canadian knows this (from post 94: “Yeah, ignoring the fact that any firearm I might own in Canada cannot be legally used in self defense”)–yet Magiver, from Ohio USA, with his question does not seem to be able to conceive of any other way. (Not meaning to pick on you, Magiver, and I hope I’m not making an unreasonable assumption about your question, but you did ask.)
It just occurred to me that one of the things we wanted, and got by force and the use of privately owned weapons was independence from you lot. Is this why you are in such a constant state of butthurt over our gun laws, ivan?
call 911. honestly, I don’t spend nights lying awake over this issue.
I was wrong above. This is the really easy answer. 
I’m wondering about something: How do Americans defend themselves when they travel outside of the U.S.?
Do diehard gun-carrying Americans never travel unless they have their firearms close at hand?
If you usually have a gun or rifle close by, do you feel uneasy when you are separated from your firearms?
I don’t know about anybody else, but when I leave the US I simply don’t travel to places where I think I would need a gun. Also, when I am outside the US, I don’t go wandering obliviously about.
Okay, sorry, but I need to ask: Do you sometimes carry a gun (or have a rifle close by for self-defense) when you are in the U.S.? If yes, when?
It seems to me that if you think you need a gun then you’re always going to think you need one, except under very unusual circumstances.
I guess I’m wondering how prevalent the “I need a gun to protect myself” viewpoint is, rather than the other reasons that people have for owning guns.
Self-defense not being a lawful excuse?
It depends on where you live…and what kind of person you are. A lot of people have all manner of irrational fears…people are horrible about risk assessment. Some people fear home invasion when the odds are astronomically against such an event…others fears are more justified (though it’s still a pretty small probability even if you are in the highest risk areas).
By and large I think that gun owners and pro-gun advocates use this mantra ‘we can use them to protect our property and our families’ to counter the gun grabbers various mantras. IOW, it’s merely an attempt to show people without a clue about guns another ‘justified use’ for the things…and one that people (or at least American’s) can understand and identify with, at least intellectually.
Personally I don’t lose any sleep about someone invading my home and I don’t know anyone who does…even some folks I know who DO live in the highest risk areas for that kind of thing. But I’ll say that worrying about someone invading your home and thus needing some form of protection isn’t the nuttiest or most improbable thing I’ve ever seen folks worry about…and I’ve seen plenty of non-American’s who worry about some pretty improbable things as well. Even Canadian’s. 
-XT
I’m an American gun owner, and neither do I.
In the US, I carry a handgun everywhere that I am legally allowed to do so. In the places where I am legally unable, its absence does not unduly distress me. On a few occasions in my life I have used a handgun to protect myself, thankfully without actually needing to shoot anybody. It takes but little effort to have it along and it is the best tool for the job when it is needed.
not for nothing that our national icon, recognizable around the world as representing Canada, is a police officer.
That was one of the things I looked for but couldn’t find in the caselaw–but then I didn’t have a lot of time to look. I know, however, that ss. 34 and 87 of the Criminal Code tend to work in tandem, and so I would imagine that a “lawful excuse” would have to be decided by the provisions of s. 34: you have a lawful excuse if you are reasonably afraid that you will die or suffer grievous bodily harm (note that this wording does not extend the defense of self-defense to protecting property), and you reasonably believe you have no other way out of the situation other than to fight your way out. In other words, if you have any other way out, you are expected to use it.
Note that both s. 34(2)(a) & (b) must be established in order for the defense to work.
Some message boards that I frequent have plenty of member who will not travel somewhere where they can carry. Many a discussion is had over what they CAN carry in specific locales such as cruise ships or foreign countries.
Yes they do, I really can’t say this is the norm however.
Spoons’ post reminded me of another difference between Canada and the US, which is related to the discussion in this thead.
Both countries use the term “Castle doctrine”, but it seems to mean quite different things.
In the US, as far as I can tell from posters on this Board (a very reputable legal cite, I assure you 
- I’ve actually cited Dopers in a couple of legal articles), the castle doctrine is related to self-defence of one’s own home: One is entitled to use force to defend one’s home, without any duty to retreat.
In Canada, the castle doctrine means that the police (or other agents of the Crown) are required to produce a search warrant before they can enter one’s home. It’s not about self-defence at all. (And last time I looked, Canadian law requires a duty to retreat when that is a reasonable alternative to the use of force in self-defence.)
So are you saying that you feel safer outside the United States than in your home country? 
I’m not trying to put words in your mouth - I’m trying to understand if that’s what you mean?
Okay. About what percentage of people in your area would you say carry a handgun?
Also (sorry for all the questions): When you say “On a few occasions in my life I have used a handgun to protect myself”, is that, say, two or three times, or more often?
I’m asking because, in over 40 years, I’ve never been in a situation where having a handgun would have made a difference, other than getting me arrested.
Did you mean to say “will not travel somewhere where they cannot carry”? Otherwise. I’m not sure I understand.
So these folks wouldn’t even come to Canada, which is a reasonably safe country and shares many common values with Americans?
That’s my impression also, based on my reading of CC s. 34(2)(b). I cannot remember any cases where this was tried though–can you?