I'm sure this has been discussed, but seeing how incredibly efficient and ruthless the soldiers appeared to be in this episode just makes me question even more how they could ever be overrun or defeated in the space of the 2-6 months Rick was in a coma.
It's going to be more like in the space of the next 2-3 days.
It'll be interesting to see how they fail. Could be due to bad leadership or decisions at a local level, or it could be due to shooting "innocent rioters" or druggie limping kids, and thus losing public support.
A week or two ago, I would have guessed that the military would fail due to a lack of understanding of the specifics, and thus storing "dead" bodies in an unsecure location, or something like that. But with the way they shot neighbor lady this week, they seem to have an idea of what they need to do.
There may also be a question of not being able to tell the difference between sick people and dangerously ill people. For example, the El Salvador mother (Griselda I think) with her broken ankle. If they try to separate her and put her in with folks dying from bites, that could lead to a small revolt against this local military.
And it may also become a case of there being too many people to take care of. The military can easily handle a small friendly neighborhood in Los Angeles. But they don't have the resources to handle 5 or 10 million or however many folks live in the LA region these days. And I'm not even sure they could handle an "unfriendly" neighborhood. There simply is not enough military to check on and protect all 300 million people in this country. The national guard is good for localized disaster response, but when you've got zombies actively trying to kill people in every single populated square mile of the country, that's a battle you can't win.
There may come a time when they simply say "not enough resupply, not enough reinforcements" and decide to fall back to their more secure home base.