It's been brought to my attention that many of you may have questions about Ukraine. I've quickly slapped a map together to help do a quick rundown
This is Ukraine.
You'll notice I've cut off Crimea. With good reason. Russia will effectively never this up. It is simply too important for them. Crimea is lost. Unless we go marching in, with guns, and by we I mean the west; Crimea stays Russian.
The rest of Ukraine, however, is less certain. Currently, pro-Russian rebels hold the area to the east of the dark red line.
The dark blue line represents the most pro-west part of Ukraine. Russia would be happy of this part of the country just up and decided to leave, as, it would result in a Ukraine that shifts towards Russia due to the loss of this Pro-West area.
The light red line shows the area that would strategically assist Russia in their current goals. This would cut off the sea as Azov, provide additional access to Crimea, and hand over important centres like Kharkiv to the Russians, or, pro-Russian rebels. This city is famous under its russian name, Kharkov, as the site of various WW2 battles.
The light blue line somewhat follows the parts of Ukraine gained after WW2. It also is more pro-west than the rest of the nation.
The purple line is the traditional divide in Ukraine between pro-west and pro-russian political forces.
That's the intro.
Russia wants Ukraine to be pro-Russia. That's the core of everything they do. The problem is that the capture of Crimea, and especially the civil war in the east (the Donbass area) have soured Ukrainians towards Russia. As such, it is likely they are more willing than usual to settle for some kind of partition; where their rebels (called New Russia) would take everything east of the purple line. Russia would still, of course, want all of Ukraine, but, this might be the line they have in mind with their current stunts.
They'd love, of course, to somehow push the west back to one of the blue lines, and have the rest of Ukraine be a happy, obedient, puppet state. This, however, does not seem likely.
How the current situation will resolve itself is unclear. My best guess is the rebels will rise again due to Russian support; and smash into the rest of Ukraine. When the Rebels and Ukraine sign their ceasefire, probably after only a few weeks of fighting, the border will just so happen to fall roughly along that line, with the US only implementing temporary and limited sanctions. Russia will then continue to try to "convince" Ukraine to come on over, but the 'current' crisis, which started in 2014, will be over, and things will go "cold" in the area.
There are other possibilities. Any such renewed war might actually see Ukraine wipe out the rebels. This would be a massive embarrassment for Putin. the Rebels also could push all the way to the purple line. A Coup could be organized without the need to reignite the civil war. That coup could fail, or, succeed. Russia could openly march into rebel held areas saying the rebels asked it. If that happens, it could lead to a straight up war between Ukraine and Russia. If that happens, either side could win or lose, but, its very much likely the Russians would steamroll the Ukrainians. In such a war, Europe could get involved, possibly with declarations of war. This could literally see Russia at war with Poland, Italy, France, Germany, and even other NATO countries, such as the UK. The worst case scenario would be the US also declares war, but, I really can not see this as a likely possibility.
The only thing I would rule out, right now, is any involvement of nuclear weapons. If that changes, I'll let you know.