Canada

And also seriously considering invading Cuba. I mean they are acting like they are somehow not in enough trouble in Iran that they want to start a war with Cuba!

Even Hitler wasn't so stupid as to want a war on two fronts. Trump thinks he can beat a country whose entire military doctrine is against US military capabilities, and Cuba has been incredibly resilient against US assault since the early 1960s. Canada might not stand up for an land invasion, but the long game favors a guerilla war that would make Afghanistan and Iraq look like a cake walk.

You know what was the difference between Iraqi insurgents vs. Afghan insurgents? Iraq had 'fancy' insurgents and an entire engineered guerilla war that had years of preparation by Saddam's forces. They had more resources and more dangerous equipment.

The Afghans were dirt motherfucking poor, an EOD who served there said that if they weren't using trash or garbage for material they weren't using anything at all. They were basically a bunch of brown, bearded, pissed off MacGuyvers.

Canada? Canada is a rich country with a preposterously overeducated population. The shit that Canadians can do far exceeds anything Iraqis or the Afghans can.

If the US invades the Canadian armed forces can fully clear out and disperse arms and explosive supplies far and wide to ex military and reservists, and despite gun laws passed and attempts at confiscations there are a fuckload of guns available in civilian hands that could be used by smaller groups, and for explosives we have tons of reserves for precursors that could be used in manufacture of IEDs.

The only thing that works in US favor is the intense surveillance and integrated intelligence apparatus that the US and Canada has. That is something that MUST go to safeguard both Canadian sovereignty and Canadian civilian safety.