Unfortunately I don't have a good answer, but I suspect it doesn't need to be a 0 or 1 situation -- having a decent percentage of the needs covered is better than having very little.
Unfortunately a trend I'm seeing in my country is that some people are calling for crippling the in-country farming industry because it is "inefficient" due to subsidization and would be cheaper to import food from elsewhere. The trend should be upwards, reducing dependence on importing and focus on local produce. Gut feeling is also that it would be more ecologically efficient although I don't have any concrete numbers on it.
One of the problems is that people normally do not want to pay for that slack. Getting them on board with spending more probably needs some convincing.
It can be done, see fairtrade coffee/cocoa. (I know that it has some problems, too, but it shows in principle that people can be persuaded to pay more for stuff, if the reason is good enough.)
Unfortunately a trend I'm seeing in my country is that some people are calling for crippling the in-country farming industry because it is "inefficient" due to subsidization and would be cheaper to import food from elsewhere. The trend should be upwards, reducing dependence on importing and focus on local produce. Gut feeling is also that it would be more ecologically efficient although I don't have any concrete numbers on it.