N a h.
I mean, the logistics of attacking USA and getting away with it and whatnot aside, you don't neccessarily need aircraft carriers.
Fair point, but I should have been more specific in my phrasing. Launching a trans-atlantic or trans-pacific invasion of the USA is extremely different from attacking the USA, without naval supremacy there is not going to be any reinforcement possible to Canadian or Mexican forces. Germans could attack Britain in WWII, but invasion was impossible until the Royal Navy & Royal Air Force was destroyed - with the US commanding the largest and most modern navies and air forces in the world, with the home advantage, the rest of the world would have to heavily militarize and the destruction of the nations' navies mentioned before would terminate much potential for any reinforcement of Canada or Mexico. The armed civilian populace and paramilitary police of the USA are a formidable enough obstacle before you factor in the US army, Canada and Mexico would not have good chances alone.
Thinking on that, how would Canada and Mexico ensure the best chances of victory against the USA? I reckon defeating any US invasions and ensuring they're not knocked out of the war immediately would count as a high priority objective, though I'm not sure how they could go about it
"Superior training and superior weaponry have, when taken together, a geometric effect on overall military strength. Well-trained, well-equipped troops can stand up to many more times their lesser brethren than linear arithmetic would seem to indicate." - Spartan Battle Manual, Sid Meier's Alpha Centauri
Naturally, the Spartans were usually one of the first two factions to get wiped out in virtually all of my SMAC games.
I've found the Spartans NEED warfare, and ironically, a good series of defeats to keep themselves competitive. Without a strong enemy capable of destroying their troops, eventually they keep producing soldiers until the industrial upkeep terminates their production lines (at least until/if they discover clean reactors). If they're continually harassing and attacking their neighbours then their production lines are kept active whilst their enemies industries are hurt fighting the Spartans' superior forces. Early to mid game Spartans rolling around Planet with missile rovers is a horrifying force to behold, by late game the Spartans are either a rape machine that can only be stopped with the probe warfare of Miriam or Morgan, the worms of Deidre or the industrial Stalingrad of Yang's magical realm - or by the late game, the Spartans ares still stuck with missile rovers whilst Zhakarov is deploying orbital space marines and singularity planet destroyers.
Also lol @ the commonwealth having any real power any more.
The Commonwealth is powerless; the nations of the Commonwealth are powerful. It would certainly be weird if the Commonwealth nations and the USA went to war, you'd get that weird situation where two sides that frequently train each other's soldiers and officers go to war
I dunno, UK does have a large navy and will soon have 2 proper carriers, and they have fair number of both SSBNs and attack subs, as well as fairly large and modern air force. Tranche 3 Typhoons are right now very likely 2nd best fighters in the world, after F-22. Canada and Australia, that also has a great navy, put together are about the same strength, just without nukes. All Commonwealth countries have relatively weak armies, though.
British army has a great deal many elite forces; I just don't see many situations that would actually get the British army from the UK to the USA. Moreover the Caribbean and Bermuda would almost immediately be lost to the USA
It is very hard to defeat the USA