The problem is the old USSR was made a permanent member of the UNSC with veto power, as sort of a Cold War detente between it and the U.S. So anything from the UN won't be more than General Assembly condemnations of their behavior, because their "binding" resolutions from the Security Council are hampered by having literal bad faith actors in positions of such power. Just another reason why there should be 1) no veto power in the SC, or at least require a majority to veto of the five, or 2) the permanent members should be abolished, and it should be straight up-and-down votes in the SC, and everyone rotates on the SC.
Sanctions are always an imperfect solution. As we saw in Iraq, it makes authoritarians kleptocrats, who just steal constantly to support themselves, at the cost of massive harm to the civilian population. I have no doubt Putin would do the same as Saddam under much stricter sanctions. It also doesn't help that we can't really enforce sanctions in that part of the world, as we have very few friends in Central and East Asia who can help enforce such sanctions on Russia. Who's gonna help us do that? China? Where are our closest bases, Kandahar, and even the Afghans don't want us there?