The governments are Democratic, but there are "legal" limitations. Each of the statelets, as part of their Constitutions (based on the "suggestions" of the WAllies) specifically folds in the elements of the conditions that ended hostilities. It is not only prohibited to take any actions toward reunification, but simply introducing legislation or voicing public suppor for the concept is illegal and results in automatic disqualification from any political or government employment for life. Think of OTL Germany's position on Nazism on steroids laced with Adderall.
Since the Constitutions also acknowledge that International Peacekeeping Forces (i.e. Polish, Vietnamese, and Philippine IPF troops) are fully recognized as having legitimate super law enforcement authority there is no chance of any politician managing to do anything legislative or even advocate for reunification.
Then there is Stettin. It will be the 23rd Century before anyone in Northwest Europe doesn't wince at the mention of that. That doesn't even consider the effect that visits to "The Barrier" has on kids who are required to make visits as part of school trips starting in 3rd Grade.
There is always the possibility that at some time in the future the A4 may relax on this, but there is still, 50 years post war, ZERO sentiment toward lightening up on the "Nazis" (the term "Germans" is usually only applied to individuals or groups pre-dating 1933, think OTL "Commies" when referring to Russians during the Cold War, but with more feeling of utter revulsion). The only support for reunification in the A4 (which is flatly the only group of states that matter) is among relatively small religious groups that take non violence as a matter of religious doctrine. The A4 political establishment listens to them very politely, counts the possible votes represented by the groups, and round files their petitions.
ATL Germany as a single nation-state is as dead as the Roman Empire.
Of course that sentiment isn't going to go away any time soon.
The problem is that the Germans didn't just kill millions, but wiped out whole cultures,
and committed multiple Pearl Harbors with some of the worst weapons imaginable on the Allies
The Nazis not only destroyed Paris, but gleefully created a home movie of it for the whole family to enjoy.
And another problem is that these events are still within collective memory.
The OTL Baby-Boomer would've grown up during the "Hot war", and would have had at least one father, uncle, older brother, or other relative fighting in the war, and a mother and older sister working some factory contributing to the war effort. They still remember, as children, the trauma of the 1954 attacks, their horror at seeing the nerve gas attacks that killed the British royal family, the destruction of Paris, and the war crimes trials. Some of them joined an ITTL peace corps to help rebuild these areas in the 60s and 70s. They met the surviving Slavic and French peoples who lost whole families to the Germans, and who would want nothing more than pulverize them into dust. American, British, Argentine, and North African Jews all dismayed at the total destruction of their European cousins.
A liberal college student may compare the A4 to Nazis over the destruction of Stettin, but the A4 have a clear, rational (from their point of view) reason for keeping Germany apart, and for dangling a reserve of nuclear weapons overhead on the rest of the world: they don't want the world to relive the horror again.
OTL, a common complaint is that America will fight a war for oil, but never a war to stop genocide. ITTL, they do that, and we still feel the need to complain over their methods.
I think there will even be hardcore nativist polices by the Poles. There might even heavy restrictions/banning of Childfree couples. For example, Polish politicians might make the claim that Childfree couples would " Rather spend their time in selfish pursuits than making sure that the Polish People do not again almost lose their identity and nationhood." There might also be an strict expectation that even if you were to be LGBTQ+, you had to have kids or adopt them and raised them in a traditional Polish manner.
The societal pressure is vastly more effective than any law. Much of the East is still a howling wasteland and the Governments actively encourage large families, usually with financial incentives.
The Low Countries and France have recovered to the point that there is no longer any population issue, but families with six+ children as far from uncommon even in major urban area. The "younger" generation is moving rapidly toward an attitude that would be familiar IOTL.
My guess is that in Eastern Europe by the present, there would be an
extreme generation gap between those with memories of the war, and those born after it. The ITTL version of millennials in the region have lives completely different than what their ancestors faced.
The average 12-25 year old in Neo-Tsarist Russia, for example, enjoys American movies, Internet, and abundance. Meanwhile, their grandparents were the ones surviving in a genocidal, slavery system, and spent their later years rebuilding their decimated culture.
They would have strong disagreements over everything, from the treatment of the Germans to going to Church.
The elders call their young people "spoiled", while the young people called their elders "racist."
But the ITTL generation of young people, thanks to the high fertility rate of the countries, would also be very large. Similar to many poor African countries, where young people make up over half the population.
So a prosperous, large, young population growing weary of their conservative elders, could easily lead to a youth movement in the present day.
I do wonder what the A4 would think of OTL Germany. I'd bet they be amazed that a united Germany HASN'T started WW3.
Honestly they would be shocked at how OTL Germany has done. Its military is negligence with it still a world leader. Its being so pacifist would be a shock. (Note I read modern Germany as fairly pacifist.)
They would literally be unable to process it. Total cognitive dissonance.
I think, if they could use a temporal window to see OTL Germany, they would weep bitterly. As much as they mistreat the Germans, it is not done out of malice, but fear over what a united Germany could do. They wish they could live in a world where Germany was a prosperous and decent nation. Of course, they would also be envious of a world where Paris is still vibrant, the Poles and Russians weren't nearly exterminated, and where a Jewish state was created.
