Canada

Imagine you and twenty of your friends have ganged up on someone in a fight. Would feel exactly as confident if they were armed with a knife as you would if they were armed with nothing?

It's not always about being able to win the fight. Sometimes it's just about making the fight costly enough that the other party decides its not worth it.

This, by the way, is exactly why our military is still pushing for the F-35, despite the very high political costs and risks that it now comes with. When you get down to the brass tacks of what an air war between Canada and Russia would look like, the unavoidable factor is that Russia simply does not have any 5th gen fighters. Even on paper their only claimed 5th gen simply isn't. The specs they've announced for the Su-57 it barely qualify as stealthy. And it's well known that Russia overstates their specs (whereas NATO tends to understate ours). We also know from what's been happening Ukraine that Russian radar is dogshit.

Everything in Russia's current air fleet, including their grand total of 6 "5th gen" fighters, would get stomped into the ground by an F-35. Stealth is a huge force multiplier. When you can kill the enemy without them even seeing you, it's not even a fight, it's just a turkey shoot. Even a small fleet of F-35s would inflict unimaginable damage on the Russian air force. They'd be limited only by their ability to maintain locations to launch from, and their available supply of fuel, parts and munitions.

Something like that dramatically alters the calculations when it comes to considering any kind of attack.