There is no "this country" capable of making any decision. The government is not us, regardless of the democracy myth. Even if I put on the minarchist dunce cap, there is nothing sacred about the Ukrainian borders. If the people of the Donbas wants to be Russian or independent or Ukrainian should be up to the people in the Donbas, not up to Kiev or Moscow. Definitely not Brussels, Washington DC, or the UN. Ukraine has been waging an internal low-level civil war for years. It's not the US government's business, and certainly not yours or mine.

Even a cursory glance at US history should demonstrate the danger of entanglement in war. See the Soviet Union, Afghanistan, Iran...