Is this hard-coded, or just really hard?

[HistoricalAccuracyMan]

Okay, so I've been wondering this for a while now...but is it impossible to completely erase a nation from the map?

In my current campaign, the only provinces France has left is Western France and a handful of microscopic islands. I have failed two naval invasions, and both Germany and Italy have failed to conquer Western France. I had at least double the amount of tonnage required both times, and failed. Italy had them outnumbered by roughly 3-to-1 (without counting any allied troops helping them) and got to 67% progress before they ultimately started losing ground and failed. The odds when Germany attacked: 1.87 million Germans plus roughly 75,000 friendlies against roughly 154,000 French Troops with maybe 12,000 friendlies. Germany got to 89%, and then their progress plummeted to 0 and stayed there until they ultimately failed a few turns later.

I successfully invaded Southern Spain, then my land army took over Western Spain. After that, I took Morocco. So now, Spain is only left with Northern Spain and a handful of African territories. I have now tried to invade Northern Spain 4 separate times. And on my final attempt, despite me brute-forcing it and moving literally every ship I had thus assembling over 4 million tons in a single invasion fleet (which was roughly 3 times the amount required to even start the invasion, and Spain's navy comprising of 3 CAs and 7 CLs only) it ultimately failed.

China is down to 2 provinces...and that's it. Japan can't seem to conquer Central China despite outnumbering them 2 million to 200,000 and I can't conquer Southern China even though my land armies launch a 4-pronged offensive from the territories surrounding Southern China. I personally feel that if there are multiple major land offensives on a single province, the defending forces should be split up some how. It is physically for 750000 troops to be in 4 places at once. Yet, all 4 of my major offensives are met with the same 750000 troop force, thus basically guaranteeing I don't gain any ground because I'm always outnumbered. I personally think that needs to change. If I am fighting 750000 troops as I try and attack from Hong Kong, I shouldn't be fighting that same 750000 troop force as another force attacks from whatever province has Fort Bayard.

@Nick Thomadis I am curious to find out an answer to this. Would somebody have to conquer all of the outlying "minor" provinces before conquering the home provinces of a certain nation, or is it not possible to completely remove a nation from the map through invasions/major offensives?

[Panzergraf]

Yes, you can wipe out nations through naval invasions and/or land based major offensives. Often the targeted nation will dissolve with one or two core provinces left, these will then become ungoverned territories. The dissolved nation can then come back later (in my campaign France came back after 1 year or so, China after 15+ years), but will then be really really weak.

Once a nation dissolves, all over seas territories like islands and African colonies will become ungoverned territory, which you can't personally initiate naval invasions against. So it's a good idea to scoop up what you can before that happens.

In the case of France, after they re-emerged, they only had Western France (which had been ungoverned, the rest was in German hands for years), and Germany promptly started land based major offensives against them. I myself (Japan) initiated a naval invasion hoping to get some territory out of this, but Germany was too fast and steam rolled them in only 4 months - never seen it done that quickly before.

Why does it some times fail and some times go that fast? I don't know. I'm pretty sure army logistics has something to do with it, but then again I've failed with 100% logistics and overwhelming numbers VS Soviet Union and their tiny army and 7% logistics, so there's probably more to it.

Short answer; yes you can completely remove a nation through invasions/major offensives, but I don't really know why it some times just doesn't work.

[Bishop120]

Yes you can wipe out/conquer all territories.  The campaign will end if you beat all the major powers by either making them collapse or conquering them.  Things really start to steam roll after a while and its not really balanced once you conquer over 100 provinces.  One thing you can do is multiple naval invasions of the same province.  If they only have 1 port then a single fleet can handle cover all the tonnage requirements for all invasions.. this is what I did.. every other turn I just say naval invade the same territory.  Eventually one of the invasions will conquer the territory then I move on to the next province until a nation collapses or I conquered everything.  I had a game go till I conquered over 200 provinces, had a GDP in excess of 5 trillion, monthly naval budget of several hundred billion.. yeah.. fun times.