Not sure. I think
@Super Bigote was not offering a ready made solution as some seem to assume, more offering a suggestion that may, or may not work. I believe he said as much. I would guess that any solution would require a heavily policed border of some sort, but what sort, where and who polices it and who pays for it are all g going to be difficult questions that those on the ground will have to grapple with.
The question of what will Ukraine look like on the ground when this is over is one that seems to have been passed over. It seems highly likely that the US and the IMF will be heavily involved in reconstruction and where that has happened before, everywhere from Chile, to Iraq and including Sri Lanka after the tsunami, a programme of privatisation, deregulation and cuts to public services have followed and reconstruction undertaken in a way that is aimed at creating a financial environment to suit US commercial interests rather and the local population. The costs for the local populations and local business in these and many other cases have been significant both in financial terms and quality of life.
By then though, the baddie will have been defeated and everyone will have left the cinema, put a few coins in a Help Ukraine tin on the way out and will not worry if that money is going to build tourist hotels rather than rebuilding peoples homes