The focus on defending itself from invasion seems off to me. Russia being invaded by anyone in Europe is really implausible, because the west prefers shady trade deals to conquest these days. I don't see it looking like a good idea to Iran either.
It's implausible to you and I from our vantage point, but not to Russians, who still celebrate VG day as one of their biggest holidays. Having a buffer between Europe and Russia has been doctrinal in Russia since at least Peter the great. Ukraine was supposed to be neutral after the USSR split. It wasn't until The EU and US started treating it like they were going to extend it membership in the EU and/or NATO that Russia stepped in. The amazing thing is that our diplomats didn't foresee the result. Or maybe they did, and their great game style thinking wanted to provoke Putin as a way to try to get his citizens to turn on him. That clearly hasn't worked. Yet.
It probably won't anytime soon :( Russians are good at bottling things in and being serviant for the longest of times. Serfdom in Russia was pretty terrible: it was pretty much slavery without the race component and it dragged on for ages. Then there were the horrors of the soviet union and Russians just took it. It sometimes feels to me like being fucked by the government is the main component of Russia's National Identity and it creates a sense of community in a way... I read Russian forums from time to time and stuff like "Things are crappy but we're Russians and we can take it until it gets better" is very common rhetoric. The majority thinks it's the West sabotaging Russia and protesting the government is giving in to the West. :(Yet.
When I lived in Budapest, the war in Kosovo was still going on, and the war in Bosnia was only recently over. Everyone lived with the general feeling that - at any moment - Russia would be back. There was this constant, looming pall from the East. Yeah, they would have to come through the Ukraine and Poland to get to Hungary, but... those parts of the Ukraine and Poland are basically Europe's version of Kansas. Lotsa farmland, and few people. On the other hand, every single Russian I knew was absolutely positive that Russia was on the brink of utter destruction, and - any day now - the entire house of cards was coming down. The Russians had so little confidence in their government, they were really fatalistic. More so than anywhere else I had been, including South Africa, Macedonia, and Bosnia. I have the strong feeling that Putin is the average Russian's Trump... a bombastic blowhard who holds far more power and influence than anybody should have let him have. But... he has survived. Through HUGE turmoil. And he has successfully expanded Russia's borders for the first time since WWI. So what a dichotomy! I can imagine my Russian friends saying, "This loon Putin has been successful at making us not die! Um... yay Putin? I guess?"