Woah, I've never had that happen to me, all nations leaving you and continuing your play-through :OOOO
To add more choices, when the Council tries to shut you down over having 2 bad consecutive months/going negative on funding, you have the choice to accept defeat or reject them and become your own power (IF you think you can self-sustain yourself). When you reject them, they will become your enemy and the council being part of the secret governments themselves, you will [once in awhile] be harassed by black suits and agents on your battlescape missions.
In this new mode, will also have the option to defend Terror-Sites or let them fend for themselves. Score no longer affects you.
The bases that were built before the Council left you will be attacked since they know of those bases. They will send the Special Forces in to go Black Mesa on you. They will only attack your bases when you reach a certain mid-high score meaning you might be ready for them. This will have a 2-part mission like TFTD, in a fun way I hope. 1st part is defending your underground base. 2nd part is clearing out the Forward Outpost base they built on the surface. Wipe them out! After they attack a base and fail, they may never try it again.
Luke
, time to make military sprites for the surface mission
All this over telling the Council the screw themselves, hehehehe. I can imagine the Council being like those cut throats in the X-Files. The Smoking man and his buddies controlling other parts of the world.
About selling your stuff when all Nations abandon you: When you sell, you sell to unknown buyers, probably illegal sales, black market sales. Dealing with rebel groups, mafias, ruthless dictators, secret cult organizations, secret government organizations, pretty much non-alien groups, because the nations will receive technology from the aliens directly. Those who don't, will come to us
Pretty much this right here. Especially in bold.
I'm not sure if it was originally planned, but clever commanders go into arms dealing. With weapons/items requiring no special resources, you can manufacture them as long as you have the capital.
The point is that, after a certain point in game time, X-COM becomes self-sufficient. Even if all countries pulled out, the only real impact is funding FROM NATIONS. Do you think I won't go into 'your' country to get that alien leader, just because you bent over? While the grunts are playing with you, WE are moving up THEIR rear. Stopped funding?!? OK. Sorry for the inconvenience, we will leave (and take this big black bag with us. YOU QUIT, not us.) After some time, X-COM no longer needs the world's support. They just get on with the job.
The 'doom meter' is a way to end games artificially. Wars and fights don't end like that. One enemy of the aliens could still make a difference, even if they had only one grenade, and had gotten to Cydonia.