It’s one of the things I posted about a lot in the old place. I speak Russian, so I followed the Russian/Ukranian news on the subject a fair bit, as they had started uploading their main opinion shows to youtube on a biweekly schedule by that time. I probably started to tune out by mid 2016 and am far less informed about what’s happened in the last 2-3 years there than I am about the 2014-2015 period.
The general course of the war was: the Russians took Crimea in the Spring of 2014 with no military opposition from Ukraine. About a month later, in some cases paramilitary people, in some cases Russian GRU spec ops units, were storming police stations and government administrative buildings all over Eastern Ukraine, and declaring autonomous republics like the People’s Republic of Donetsk and the People’s Republic of Luhansk. The Ukrainians said enough of this shit and sent their military in to encircle and disperse these Republics, and they had a fair bit of success in the early summer. It was not uncontroversial, as they had to shell their way in, killing hundreds of civilians in the process. Eventually, seeing that these Republics were going to fall, the Russians intervened in far more dramatic ways; they sent in a buttload of technical equipment, they reinforced the militias with “volunteers” who happened to be ex Russian soldiers, FSB colonels in some cases. They provided anti-air capability, which at first was used to take down a few Ukrainian military planes, but then there was the MH17 incident in which a Russian BUK system was used to bring down a commercial airliner killing 300 people.
Anyway, the Russians/liberated Donbas folks started to beat back the Ukrainians and pushing them back. In certain battles the Russians used actual regular army troops such as in the battle of Ilovaisk in August 2014. I think the most strategically significant battle happened in early 2015, the battle for Debaltseve, where they basically encircled a bunch of Ukrainians defending a key railway or something and forced them to retreat.
This is already TMI, I’m pretty sure by mid 2015 a frozen conflict scenario started to emerge with a relatively stable front marked by sporadic cross front shelling. To answer your question: I’m sure they wanted lethal aid, Obama hesitated for reasons, I don’t remember having a super strong opinion about it but I was okay either way because lethal aid wasn’t going to affect Russia’s calculations that much, unless I suppose the US ran the full Afghanistan war playbook against the Russians, but even stable genius didn’t put that on the table.
Long story short people like McCain were fainting about Obama’s weakness 24-7 at that time, while the truth of the matter is that he handled that conflict about as well as possible, given that the Ukrainians were not NATO allies and for Russia, Ukraine is like the origin of their civilization.