If you're a russian expatriate, you might be interested in this little fact: right before WW2, there were a _lot_ of voices in the USA advocating _carpet-bombing_ the USSR with nukes preemptively. Just, you know, because they happen to be a _potential_ adversary.
What stopped them was when the USSR finally got their own nukes and you couldn't bomb them without getting bombed right back.
Just to put things into perspective: The USSR had until that point behaved like a pretty loyal ally. Sure, they had some different ideas about the economy, and securing their own sphere of influence, but by and large they were still grateful for the help in WW2. They stopped when they were told to stop, and stuff like that.
E.g., the reason why today there is a North Korea and a South Korea is because the USSR got asked by the allies to declare war on Japan after it's done with Germany. The USSR had little to gain there, but it honoured its treaty obligations. So it did take Manchuria from Japanese (dealing quite a bit of economic damage to Japan), and handed it over to China. And then proceeded to take Korea from Japan too. So the USA got a bit scared and asked Stalin to stop at the 38'th parallel. Noone actually expected that Stalin would actually stop at the 38'th parallel, but again, the guy actually did what his allies wanted, and actually stopped there.
E.g., a little known fact is that on 10 March 1952, Stalin actually proposed to let Germany reunite, if the result stays neutral (i.e., doesn't join either block.) It was the western powers that refused that.
Stalin was a bad guy, but in regards to the western powers he was _not_ at the moment the enemy. The USSR was in fact still by and large an ally of the USA, a member of the alliance that had just won WW2.
Even the later degrading into Cold War was slightly more a result of USA brinkmanship games than of USSR's doing any evil. The western capitalist world had gotten its panties in a knot at the idea of communism and became obsessed with opposing and thwarting the USSR at every step. The USSR was treated as the enemy, complete with violating their airspace daily, which helped deteriorate diplomatic relations very very fast.
I'm not saying that to defend Stalin or communism, I'm saying it to put it into perspective who did those guys want to nuke: an _ally_.
Without the USSR developping a counter-threat quickly, chances are you wouldn't even be here to brag about being a russian expatriate. Unless you immigrated some time in the 50's, you or your parents might well now be casualties in a statistic, because someone preemptively nuked Russia wholesale.
A missile shield turns all that right on its head. If the USA had a shield back then, it would have nuked Russia by now. The moment one side is immune to retaliation, it can threaten the other side with impunity, or even make good on those threats.
At any rate, maybe that little historical detail is why Putin is now getting his own underwear in a knot.