> I fail to see any credible alternative to "dangling NATO membership".
You mean other than a policy of neutrality, much like Switzerland and Finland (and, to a lesser extent, Ireland) have pursued?
This would mean training a defensive army with the clear message that the cost of invasion would be so high as to dissuade such imperialist endeavours. The Swiss developed this half a century ago [1].
Switzerland is highly mountainous and 2 out of its 3 big neighbors historically could not agree with anything the others proposed, which most likely meant that at least 1 of them would support the Swiss against the other 2 (at most) invaders.
Scaling Swiss neutrality worldwide is unrealistic.
Most countries don't have these kinds of luxuries.
The Swiss and Finnish geographies are uniquely suited to holding out against a much larger force. Ukraine has to try to do that now, but that doesn't make it a good strategy for them to have planned on.
(The other thing that makes Swiss neutrality work is that the bulk of the resources that they have that matter are human, and therefore hard to claim when conquered.)
Don't cherry pick - Yugoslavia initially pursued it, too. And there are similar ethnic/religious tensions all over eastern europe, but they were not acted upon when western integration was available.
You mean other than a policy of neutrality, much like Switzerland and Finland (and, to a lesser extent, Ireland) have pursued?
This would mean training a defensive army with the clear message that the cost of invasion would be so high as to dissuade such imperialist endeavours. The Swiss developed this half a century ago [1].
This is not a new, untried or crazy idea.
[1]: https://en.wikipedia.org/wiki/Total_Resistance_(book)