Canada wins all rounds, except potentially R6.1. All scenarios in which Canada has prep they win, easily. I really want to take this opportunity to really ingrain how insanely powerful modern technological advantages are. People talking about "numerical superiority" don't understand the first, most important thing about modern conventional warfare. Moving large armies requires large supply trains. Large supply trains are easily disrupted by aerial superiority. Aerial superiority is heavily dependent on quality and technological sophistication, not numbers.

"But Canada's planes aren't that new" - maybe not the basic design, but the missiles and the radar technology is way ahead of anything anyone fields in any of these scenarios. Essentially, the ability to detect and fire upon the enemy with superior missile technology (not to mention SAMS) guarantees victory. The F-35s are just icing on the cake - their only limitation is ammunition. Even 1980 America will not be able to detect them, outrange them, or really do much of anything about it.

Let's run through a few of the scenarios to really dig into just how modern technology plays out on the battlefield.

R5: Canada can easily make nuclear weapons. They're one of the largest economies of the world, and making them is a lot, lot easier than people seem to think. Most nations don't because of international fallout, and the fact that other powers would attempt to prevent them. South Africa, Pakistan, North Korea - do any of these places strike you as more technologically sophisticated or educated than 2016 Canada? They have nineteen nuclear reactors, and building those is actually harder than making nuclear weapons.

Further, 1948 America has no method of delivering their nuclear weapons that Canada cannot detect with a year's prep to build a radar system, and then shoot down.

But ok, let's set aside nuclear weapons and look at how a 1948 military actually plays out against a 2016 one. First, America cannot instantly send a huge invasion force over the border. Invasions require preparation, staging, the gathering of supplies and the making of plans. During this time the (expanded and improved over a year) Canadian missiles and planes will basically wreck every highway and major road, destroy fuel and ammunition centers, and reduce the American military to what their several million men will carry. Let's say that despite this, the large American infantry force advances...... into the enemy defensive lines which feature the following.

A: Night vision, and considerably longer ranges of engagement by modern assault rifles. The ability to launch major night offensives will absolutely decimate the American military. Body armor, and far more advanced anti-tank personnel weapons.

B: Superior landmines, drones, automated machine gun nests, superior engineering and construction technology leading to a more rapid construction of all sorts of defenses.

C: Massively superior artillery, both in range and scope, means the American military will have to maneuver underfire well before they can respond.

D: The tanks. Can we talk about the tanks? Armor was obviously a huge deal for 40's militaries, essential to how they handled offensives. How do you think WW2 armor is going to stack up against (Or any armor we're discussing here) , tanks with reactive armor, night vision, laser rangefinders, an ability to engage out of line of sight, and generally just better in every way? Poorly. Very poorly. Numbers don't matter if the enemy can attack at night, totally out maneuver you, and outranges you.

There's so much here I can hardly even begin to cover it. Modern CBU cluster munitions would make mincemeat of any tank forces that are being discussed. The USSR would probably win in 1975 because this is the only scenario in which Canada cannot prepare sufficient anti-missile defenses, and just gets exterminated by nuclear weapons. In all scenarios with prep, they stomp. Thirty years of modern technological advantage is equivalent to a hundred or more in any other era.