No, "this" meaning the present situation in the region. And I'm not asking about a hypothetical, but the actual reasons are that people who support military action. And what is it exactly you personally hope it would achieve.
I would be interested to hear from anybody from Ukraine to USA to Russia.
No right or wrong answers, I'm just interested in perspective.
For myself since I'm asking the question: I'm in a western country and I don't support sending my countrymen to war. For a number of reasons, primarily I don't think the western neoliberal ruling regime (not talking about one political party or another, but the non-partisan support for wars and interventions by many western governments for many decades) can be trusted with war or interventionism. It has almost always been sold on utter lies and deceit, and almost never turned out for the better of the people involved.
It is sold to us on emotion and outrage and urgency and this kind of thing, but very little calm rational and considered arguments and debate of pros and cons and risks and goals ("Putin is like Hitler and must be stopped" type of rhetoric really does not describe a goal of aim of a military action adequately) . Now I have no doubt there are many very good arguments for the people of Ukraine, the country of Ukraine, the containment of bullies and dictatorships, etc., that could help make the case for military action in this case. However I also know that the ruling class have absolutely no interest in the actual well being of the Ukrainian people or the security of the average person in Europe, or a moral duty to stand up to bullies and dictators, or human rights. Because if they did we couldn't explain their actions and inactions with Saudi, Yemen, North Korea, whatever. They are happy to claim they care about those things if by coincidence they might be seen to align with their agenda, but we know they don't care.
So we know the warmongers are lying right off the bat, this is not really disputable. This doesn't make the case for war wrong, but it does (to me) make it much harder to see what is going on, and I think caution should be applied in such cases. But I do acknowledge the problem with appeasement and the need for decisive action and the fact that we will never have all the information so again this is not a criticism of others who feel differently.
What I would look at for example is Crimea, which of course fell to Russia in a similar way during the Obama administration in which there was also some people calling for war.
If there was a major war over Crimea back then, would the situation for Crimea, its people, Ukraine, and everybody else involved with the war be better today than it is now? If Crimea was occupied by Russian forces would it have meant civilian collateral deaths? If many people in Crimea were pro-Russian separatists, would that war have meant bombing the people of Crimea? And what would the end game be? Would we still be there? How many people would be dead? Would it war there have dissuaded Russia from this action? What are the similarities with the regions of Ukraine being occupied now? I have seen almost no analysis of this with hindsight, I'm sure such analysis exists, but it is a concern to me that the warmongers have not taken it and made it front-and-center of the discussion. It would be a very good data point for justification of any action now.
Finally I would not support war unless a significant number of Ukrainians particularly from the region take up arms against Russia and start fighting. They are the ones who have the ultimate moral authority about whether force should be used to protect their land, and they have the first responsibility to fight for it. Sounds cruel and it is, but crueler in my opinion is to first send people who have no relationship to the place to fight.
EDIT: and when I say warmongers I don't mean people who are pro war in any situation, I believe war is sometimes justified. I was purely talking about those in the ruling class who are warmongers.