Easy loophole. Tell Eastern European countries they can do whatever the hell they want. I think several have a score to settle with Russia.
But seriously if Putin would prefer to not have deep strikes into Russia, then maybe we could meet him halfway – send a NATO coalition to Ukraine and steamroll Russia out. Including from Crimea.
… That’s a very good point actually. Vacuums are rather insulating. Without convection cooling from a fluid, you’re relying on radiative heat transfer for cooling, and that’s piss poor.