>Go out to where? It's gong to have to overcome the pressure of the physical bottle, which is going to be way over 1. The gas will go into the bottle. The squeezed bottle will just be filled with CO2 to the point of deforming until it either reaches the equilibrium pressure. Of course if you remove almost all the air the CO2 will escape the soda but the pressure in the bottle will not go over one atmosphere so you have perfectly flat soda.

>Let's use the example of a metal bottle, how does a drink go flat in a metal bottle without any air in it? You don't even need a metal bottle, just use a normal unopened bottle, how does a normal bottle of coke go flat? It doesn't since there is only a tiny amount of air for the CO2 to go into.

The CO2 doesn't go "into the air" it goes "out of the soda" which may seem a small difference but it is the gas pressure in the bottle that keeps the CO2 dissolved and this the soda carbonated. If you placed that in an open vacuum with no air at all it would go flat even faster because of the pressure differentiall. (There is less pressure holding the gas in solution) the CO2 will continue to leave the soda until the gas itself builds up enough pressure to hold what's left in solution. If there is a lot of air in the bottle it will take less CO2 to build up that pressure. If you remove the air it will take more CO2 to build up that pressure. Squeezing a bottle didn't reduce its volume, only the volume of air inside that must be filled by CO2 if it is ever going to reach equilibrium pressure. If you squeeze a bottle from the store before opening it you will know how much pressure it takes to keep CO2 in solution for "full carbonation" there is no way for a bottle with the air evacuated will resist anything close to that much pressure so as the CO2 is released the bottle will start expanding to accept the CO2 but there is not enough CO2 to replace all the air quizzes out do the dogs hours flat long before at reaches equilibrium pressure.