I believe that this game could use a new way to lose: if 50% (8 in vanilla [UFO] and {TFTD}) or more countries sign pacts with the aliens, the X-COM project will be terminated. The alien pacts call not only for ceasing funding towards X-COM, but also applying pressure for its closure and at 50% or more, the pressure reaches a point in which the countries vote for the projects complete termination and convince the remaining sponsors to follow in their footsteps.
If at the end of the month, the number of countries that signed pacts reaches one below the 50% mark, a message will read, "Already many of your sponsors have signed pacts with the aliens. You must defeat the alien incursion soon before any more [nations] {organizations} sign secret pacts with the aliens or X-Com could face termination."
At the end of the month, where enough countries have signed pacts, the monthly report will read, "A majority of your sponsors have signed pacts with the aliens and unfortunately, they have forced the [council of funding nations] {committee of funding organizations} to ultimately terminate [the X-Com project] {funding X-Com}. They have convinced the rest of the nations to deal with the problem as they have. We can only hope we can come to some accommodation with these [apparently hostile] {ancient} forces and the general population will come to terms with these [alien] {aquatic} visitors."
This way to lose practically adds a time constraint to the game (though it is variable), in which you must access and complete the final mission before too long or be defeated.