hydroptic

https://en.wikipedia.org/wiki/Operation_Unthinkable

https://en.wikipedia.org/wiki/Operation_Dropshot

Both probably qualify as noncredible and I don't actually think either should have happened.

… unless?

Opinion piece by professor of political science Alexander J. Motyl.

A synopsis of sorts from the first few paragraphs:

Analysts of Russia differ about many things, but the most important difference concerns their interpretation of the roots of Russia’s ongoing aggression. One side argues that Russian history and political culture are to blame — or, to put it more simply, uniquely Russian characteristics are the cause of Russian aggression. The other side argues that the causes are not uniquely Russian, but typical of the behavior of certain kinds of states, regimes, societies and leaders.

Unsurprisingly, historians of Russia and Ukraine tend to fall into the first camp, while political scientists with a comparative bent tend to fall into the second camp. Equally unsurprisingly, the first camp sees no easy solutions to Russia’s current behavior, precisely because it’s just a continuation of an age-old pattern of Russian behavior inspired by the inalterable Russian soul.

[…]

In contrast, social scientists are often somewhat more bullish about Russia’s prospects of change. Other countries have abandoned centuries of authoritarianism, so why not Russia? It may not be easy, but it’s surely possible, with the right array of policies and under the appropriate conditions.

[…]

So, who’s right? Alas, both perspectives are, and that’s why there is no easy answer to the problem of Russian imperialism.

The Curta mechanical calculators were designed by the Austrian engineer Curt Herzstark, with initial designs from the early 1930s – being half-Jewish, he finished the design while being held prisoner at the Buchenwald concentration camp.

Here's some quotes from the wiki article:

While I was imprisoned inside Buchenwald I had, after a few days, told the [people] in the work production scheduling department of my ideas. The head of the department, Mr. Munich said, 'See, Herzstark, I understand you've been working on a new thing, a small calculating machine. Do you know, I can give you a tip. We will allow you to make and draw everything. If it is really worth something, then we will give it to the Führer as a present after we win the war. Then, surely, you will be made an Aryan.' For me, that was the first time I thought to myself, my God, if you do this, you can extend your life. And then and there I started to draw the CURTA, the way I had imagined it. — Curt Herzstark, Oral history interview with Curt Herzstark (1987), pp. 36-37

[…]

The Curta's design is a descendant of Gottfried Leibniz's Stepped Reckoner and Charles Thomas's Arithmometer, accumulating values on cogs, which are added or complemented by a stepped drum mechanism.

Numbers are entered using slides (one slide per digit) on the side of the device. The revolution counter and result counter reside around the shiftable carriage, at the top of the machine. A single turn of the crank adds the input number to the result counter, at any carriage position, and increments the corresponding digit of the revolution counter. Pulling the crank upwards slightly before turning performs a subtraction instead of an addition. Multiplication, division, and other functions require a series of crank and carriage-shifting operations.