That "half of NATO" has nuclear weapons.
The US hasn't experienced a war on it's own soil in living memory. Americans shit their pants when they see a couple of drones over New Jersey. And Americans don't have the will to endure a long drawn out occupation even when there's an ocean between them and a war. Canadians will endure it, because we would have no other choice.
This would be a war of betrayal. Trump would need to have Elon Musk purge the US military of anyone with even an once of honour and courage. Currenttly Trump is demanding Canada to defend the US border for him. The US would need to defend it's border, and that's a long border. You'd also need to have checkpoints in the US where soldiers will check your papers because Canadians would be trying to infiltrate the US and hit the soft targets everywhere. There would be raids on your houses to find and Canadians or any sympathizers. How willing are you do have these things happen?
Because it would be betraying an ally, the US would have zero allies in this war. Canada would get lethal aid from Europe and likely from Asia too. And Canadians know how to make an IED. Because our soldiers served in Afghanistan. Alongside the US military that's going to betray the soldiers it fought alongside a few short years ago. And why? Because of the whims of a deranged old man? So you might have a slight morale problem.
While you're looking at troop strengths on spreadsheet, we're looking at the willingness of Americans to do what would need to be done for decades to succeed in occupying a neighbouring country. We only need to outlast you, while you need to have the will to watch young people coming back from the north in body bags. For decades.
The chance of the US winning a war like this is basically zero.
Is your brain so twisted you don't see the President of the USA saying he wants to annex my country?
That's real, it's not propaganda. He said it. I'm looking at the words of the of the President of the USA, what are you looking at? Fox News?
And the only scenario where I'll be going to the US is if there is a war, and I'd only be going there to blow shit up. I don't give a shit about how nice you think your country is, if your president betrays us (as he's constantly saying he wants to do) I'll be doing everything in my power to destroy your nice comfortable life. That's what war means and you need to start looking at this for what it is. This may be a game for you, but it's our country for us. We will defend our country through every means available to us.