Moscow was surprisingly capitalist. They noticed they could sell their resources to the West for dollars or give them away to their communist "allies".
Also related fun fact: the GDR started to refurbish and use old steam locomotives again as a result of the oil crisis. I remembered seeing those regularly as a child, and then later wondered what caused this anachronism.
« Remember: it was Russia which tried to blackmail Germany by shutting down the pipelines » — I do not remember. I've never heard of that. What I do remember is there was maintenance work being carried out, for which gas flow had to be reduced; some said it was routine work, others pretended there was a political motivation. There were also unprecedented and illegal seizures of Russian assets before that.
« the Ukrainians settled the matter » — This is the yacht story, which I think you're too smart to honestly fall for. The decision to carry out an act of sabotage that constitutes a casus belli was taken in London or Washington (whomever you give precedence in this matter). Biden loudly and openly bragged about "putting an end to it" on February 7, 2022 in the White House, in presence of Scholz. And US companies stood to profit from it, as did "Nine Eyes" members Norway and the Netherlands.
There was no need for any Ukrainians to be involved in any way. The story is seized upon in Germany to deflect from an embarrasing and discomforting reality:
Germany's alleged friends aren't, and Germany's leadership has been collaborating with them against Germany's national interest and continues to do so. And while I don't know whether there was blackmail involved I do know that there was terrorism involved (the GermanWings crash on 3/24/15, ridiculously blamed on "pilot suicide").
Lol, ok wacko... whatever you say.
To return the "compliment", consider whether it rather applies here … 49386949. And remember to "flag".
Although I don't know if that was more a case of "we really ought to take the grinder to that mould and stick something else on", or what.
Mind that that didn't only matter for GDR, but also East Prussia etc. which was important for all the displaced people from now-Poland, Sudeten Germans etc.
The region that was once East Prussia has now mostly been ruled by Russia since longer than almost anyone there has been alive.
Till then (West) Germany had quite inflspecific wordi g. The constitution says "German citizen is, who is German" and they kept the old Empire's citizen law to have continuity.
That's one of the reasons why reunification between East and West bad go be done so quickly (from falling Wall No. 9th 1989 to reunification October 3rd 1990) as East Germans could migrate to West easily as soon as the Wall fell and promise of quick unification was a key promise to prevent even bigger migration.
The first sentence is true, and is what I know. The second economical leg of this sentence is new to me.
Basically, Hallstein Doctrine was what "One China" politics is. The BRD assume that is is the sole legitimate (since democratically elected) government. For example, someone from east germany fleeing to west german already had the (west) germanship citizenship, no paperwork needed to get it.
However, Hallstein doctrine had --- to the best knowledge ... very unspecified reactions. Germany e.g. stop diplomatic relationships with Cuba. But not economical ties, I know that my father continued to smoke Havanna cigars (eeeek!). They stopped diplomatic ties with Yugoslavia ... but all the Winnetou Films were recorded there, and it even became a holiday destination for west germans. Also all payments continued, it was not an economical embargo.
In the case of Egypt it could be seen like that. When Egypt accepted the state-hood of east-germany, then West-Germany broke it's diplomatic ties AND stopped its economical aid. I'm not aware of it stopping buying oil from Egypt, thought.
Fan fact: there is also two inverses of the Hallstein doctrine. The first one is the Ulbricht Doctrine. That doctrine mandated that socialist countries mustn't normalize their diplimatic ties to west-germany until it recognized east-germany.
And the second inverse is that other countries only saw west-germany as the legal succession of the 3rd Reich and even the german empire. So it was West-Germany had hat to fulfill contracts of that time. Except for the reparations. The USSR took (or stole) more stuff from East Germany than the western allied forces took from West Germany. About 30% of the industrial infrastructure was removed, e.g. 11800 km of railway tracks. And even after they stopped removing the infrastructure itself, they still demanded a percentage of the production.