My tone comes off angry, but I'm not actually. Apologies. Perhaps... frustrated? At the end of the day I think if NATO were to come to an end Canada would remain generally unaffected because of other treaties that involve just the US/Can and US/Can/Mex. We'd probably get dragged into a few wars in Europe, but that happens now anyways - it's the price of having the Queen on our cash and a legislative monarchy.
I'm on the reply page so I'm sort of moving backwards through your comment with responses.
Thus the argument: treaties are things you have to abide by even when they're stupid. There is nothing in the NATO charter that says "mutual assistance if we feel like it." Which calls the whole treaty into question.
I think there's a distinct difference here between the example you're citing and the entrance of the US into Iraq, and not just where the theatre of war was. In your example, Britain and Russia get dragged into a defensive war because Germany wanted parts of France it decided are part of "Old Prussia", areas like Burgundy, Alsace, etc. Italy and Austria-Hungary are dragged in because Germany knew that it would be unable to win. I wouldn't say that Italy and A-H were "obliged" to come in on their treaty, but I would say that it was in their best interests to do it - If Germany loses there's no point in having a treaty with them because they're weak, and if Germany wins then there's no guarantee they'll honour it for you because you reneg'd, so there's no point in having a treaty.
In Iraq, I see NATO as the Italy and Austria-Hungary to the US's Germany. Iraq, in this case, is France without any friends except maybe Saudi Arabia. The US doesn't need anyone to go in with them, and is just bringing their buddies along because they want to make sure they look legit while they do this shady thing. Are treaty holders obliged to follow in with aggressive action when the original purpose of the treaty was defensive? Good question. I imagine it's covered in NATO documents somewhere, or else in UN documents - Somebody's got a rule about it, I'm sure. Regardless, NATO wasn't at the same impasse the Triple Alliance was in - The worst that the US would get was a blood nose - which it did - by having to admit there were no WMD's.
And the argument is that those proxy wars are irrelevant to Europe, and that the problems of the Near Abroad do not belong to the US.
Well I would argue that the current proxy war in Syria is rather relevant to the EU, considering it's one of the largest destabilizing elements of the EuroZone at the moment, and policy regarding refugees from that same war is one of the primary reasons European leaders are getting elected and booted out at the moment.
Russian aggression in Ukraine was given an excuse because there were talks of Ukraine joining NATO. It is still directly affecting Europe right now not just through the continued tension in Ukraine, but also because a large portion of Europe still gets its natural gas from Russia - occasionally Russia plays a power game and either raises prices or turns off the tap altogether.
Are these situations what NATO was for? Idunno, probably not. But it's what we have.
What you're seeing is an illustration that the United States wants a military strong enough to defeat literally everyone else.
I understand the theory behind having an army of that size, But I see that encouraging someone else to have more military spending is a way to guarantee more spending of your own, which is already functionally unsustainable for the US. In your strategy you have to match everyone else in money spent, dollar for dollar. If the EU suddenly doubled its military budget, you would have to add another percentage of GDP going towards your military - You'd bankrupt yourself trying to keep up. It's nuts.
Also, what's the threat? Large scale ground war the likes of WW2 is unlikely to happen again - technology has changed the battlefield too much. Sure, having the latest and greatest tech is going to be a big advantage, but you currently have a gigantic infantry which will end up doing not very much on the field of battle if the US ended up going to war with China, say. It's way easier to target other countries at their vulnerable tech centers, their markets, their classified information. As much as the US has an advanced military, the way its primary function is still set up is going to leave you guys like the proverbial giant with feet of clay - overspending like crazy to get nowhere near the result.
Then again, I'm talking as if I'm some military expert - I'm obviously not.