@Kinnison
IMHO
A strategic war of finances and support isn’t the same as a shooting war.
No-fly zones have to be enforced. It was tried with Syria with little change in the outcome for that country. Plus it requires having fueling stations in adjacent countries or sea. Which in this instance will be seen as a direct provocation. Putin knows this and has outplayed the west so far. But his resources aren’t infinite. He may find it more expensive in both manpower and cash to keep this up.