I've seen the use of "A4" in many contexts
https://en.wikipedia.org/wiki/A4 but none of them makes sense here. I assume what you means is "the four Allied powers." But what caused them to fail to reach agreement on unifying Germany was not that they were "unforgiving" of Germany, but that each side wanted a united Germany to adopt its own social system. As Stalin told Djilas, "This war is not as in the past; whoever occupies a territory also imposes on it his own social system. Everyone imposes his own system as far as his army can reach. It cannot be otherwise."
https://en.wikiquote.org/wiki/Joseph_Stalin This was of course only approximately true (Stalin did not attempt to impose socialism on eastern Austria, for example) and it is conceivable that the USSR would have agreed to a united, non-Communist Germany in order to prevent the rearming of West Germany (which far outstripped the Soviet zone/GDR in population). There is strong evidence that the famous Stalin note of March 1952 was simply a propaganda move neither expected nor intended to be accepted; but in 1947 there may have been a real chance for German unity, as I note at
https://www.alternatehistory.com/fo...tarised-postwar-germany.426392/#post-15655789 Also, after Stalin's death, not only Beria but Malenkov may have been willing to consider a unified Germany. See my post at
https://www.alternatehistory.com/fo...lve-the-issue-of-berlin.391803/#post-12607513