@Romulus:
I mean, in chess there is a particular combinatin of move, that is started with the sacrifice of a own piece to force the enemy in a series of forced move or oputting him in a bad position, in order to chekmate the enemy King.
One thing that may be similar to a sacrifice in chess is the 1-2 punch that is often needed to crack a capitol.
For example, both Japan and Germany might have 80% as big a force each as Russia has defending it. Neither one can take Russia down on their own. However, Germany can launch a suicide attack in which it loses all of its forces, and reduces Russia’s strength by 50%. Now Japan has more than enough to wipe out Russia, because of Germany’s sacrifice.
Not a perfect analogy.
On the topic of defending the capital at all costs - I have played some Russian players who just keep a huge stack in Russia, even though no major axis force is bordering Russia. The result is that the front is weakly defended, and a bunch of units are sitting where they can’t kill anything - you may as well not have them!