he was signing up to be a member of the Nazi party.
He never signed up, that is the point. His name and the name of others was copied from the list of young recuits that was drafted in the last months of the war.
Kohl [...] had a pathological hatred for Serbs
This is probably one of the most hilariously wrong characterizations I have read here on pf. Not only was the defining lesson Kohl and Genscher learned from their war time experience that you had to reach out to your former opponents, and they abhored war so much as it was pragmatically possible for politicians. Kohl and Genscher were barely adults (or in the latter, still a boy) when the war ended, and they became commited democrats, learning the right lessons from Germany#s past.
Kohl also famously got along well with several Slavic politicians, including the first democratically elected PM of Poland and Gorbachev. In fact Kohl did a lot to deepen ties to the former enemies in the East and supported their newly won freedom.
Honestly, the history behind Germany's recognition of Croation is pretty straightforward. Initially no one in Bonn took much notice of what happened in Yugoslavia, because they were more concerned with Eastern Europe and German reunification. Then when things started to get messy, Kohl initially wanted to wait for France and the USA to make the decision, however both dragged their feet on it. He was then convinced by his advisors, including Genscher to recognize Croatia with those irrefutable arguments:
-Croatia had been forced to become part of Yugoslavia to begin with. So recognizing it would correct a historical mistake and restore historical justice.
-Croatia's struggle for independece was not much different with the countries in Eastern Europe leaving the yoke of the SU. Bonn could not support those attempts while ignoring the plight of the Croats.
-There was no public support for staying in Yugoslavia among the Croats. As one of his advisors put it, telling the Croats to wait would be like telling the East Germans to stay in the GDR.
Those arguments hold still up today. The only argument that turned out to be false was that a recognition of Croatia would convince the Serbs that their cause was lost, due to the diplomatic isolation of the other countries and force them to negotiate a breaku-up peacefully. Unfortunately Milosevic was not Gobarchev, and instead the Serbs aimed to keep Yugoslavia together by force.
