Putin has allegedly made remarks about being able to conquer Kiev in two weeks, and Western news jumped on it.
This highlights one worst case scenario for the Ukraine conflict; the West might decide to not allow the Ukrainians to lose, but without kicking out the Russians itself.
This wouldn't be a new pattern:
It happened already in the Yugoslavian Civil War, when the Muslim Bosnians and Sarajevo in general were not allowed to lose. They lacked the means to win with what little support they received from the West, so the war grew old and ugly.
The same was repeated in Libya, when the rebels were not allowed to lose, even with a UN mandate. The West had to be involved directly to keep them from losing, so it grew impatient and ultimately through mission creep it turned the endeavour into decisive anti-regime support.
The Western powers again did not like the idea of rebels losing in Syria, but this time it didn't need to be involved so much, and remained patient.
The same pattern of not allowing the preferred civil war faction to lose was already attempted in 1991 when no-fly zones were established over Southern and Northern Iraq, but the meddling was still too inexperienced and the amount of effort required to keep the Shiite rebels from losing was greater than anticipated. Eventually, they lost - but the American right wing never forgave this and reversed the fortunes a decade later.
Now how could the West keep the Ukraine from losing, thereby keeping that stupid civil war going for years and creating an huge, decades-lasting rift between Ukrainians and Russians?
The intro pointed at it; don't allow Putin to capture Kiev. A single brigade of Western troops protecting Kiev in addition to supplying weapons, vehicles, tools and ammunitions of war could keep the nonsense going for years.
I fear this may happen, for it would fit into Western great power gaming patterns of behaviour very well.