@JamesAleman:
If you(an axis player) invade a neutral and fail to capture it; it joins the other side (the allies). It is not pro-allied, it is an ally, like Dutch territories are.
I never picked up on this before. Thanks for clearly pointing it out, James.
So if you attack a true neutral, it is no longer neutral, it joins the other side. All the OTHER true neutrals in the world are still neutral, but become pro-enemy Alliance, so their “no-fly zones” are still in force. But the invaded true neutral is now “in play”. So your enemies could then move ground and/or air forces into the attacked country, as it is no longer neutral. However, until the opposing side moves ground forces into said territory, no playable power controls the attacked territory and no one collects income from it until conquered or claimed by ground forces, as applicable. Got it now, then.