not really, there are no legal successors of roman empire. As for Rome, Well Istanbul/Byzantium/Constantinople was historically a Greek city what doesn't make automatically Turkey Byzantine Empire's successor.
Reference to Rome - only US and III Reich did it in all aspects, architecture, military, technology, world conquer politics. I wonder if end will be alike?
They are legal successor to roman empire!
The Franconians were a big and powerful german tribe allied with romans as a "foederati". After 3. century they overtook slowly the roman empire, during this time nearly 50 % of all western roman troops were germans and many germans were in high positions in Rome. Odoaker (was not Franconian) was a german tribesman and general of Rome, he overtook the power of german tribes settling in Italy and was more powerful, than the last Caesar of Rome. Odoaker made an end to roman caesars. So the Kings of Franconians, who overtook of german tribes and Odoakers "Kingdom of Italy" were in tradition of the kings of Rome and the Caesar of the Holy Roman Empire of German Nation had his approval from the Pope, the bishop of Rome. This is the first empire, it was destroyed by Napoleon, later the 2. empire was found and ended with the end of WW1. Hitler called his empire the "3. Reich"...I hope you understand why!
Funfact by the way, people from middle of Italy to middle of Germany are genetic the same ethnicity more or less! In northern Germany the DNA is different, belonging more to Scandinavia.
Sofia Palaiologa was the nice of the last caesar of Byzanz and married to Ivan III Grand Duke of Moscow. Nearly the whole orthodox ekklesia emigrated to Russia. Russia is successor to Rome (Eastern Roman Empire/Byanz), because of the marriage of Sophia with Iwan III and the leading orthodox ekklesia moving to Russia.
Italy...is more or less clear!
All official successors to Rome were allowed to have the eagle in the flag and seal, according to heraldry. The eagle was the sign of the Roman Empire. Russia has an eagle as seal and sign, Germany has, Austria (part of German Empire later independant) has..and funny Albania has an double headed eagle, because first Albanian leader after turkish occupation was an Austrian Duke or something like this. Poland is linked to Bohemia, like Germany...so they have an eagle.
USA had long discussion about the national seal...first suggestions had no eagle. It took 6 years for the final version of seal. The creators had no really clue about heraldry ;D really! So the seal is very storytelling, pseudo-epic, mawkish but....it is an artificial seal.
So Pantheon in Paris is NAZI architecture? It's called classicism!!! Many buildings in the 18. and 19. century are build in the classicist style, for example the British Museum. Best example for russian classicism is St. Peterburg...the old city (mix of baroque and classicsm)! That's why the representative building of USA look so "roman" they are all build in the classicist style, not like in France (Versailles), Spain, Germany (Sansoucci) or Britain (Kensington)...earlier means baroque architecture. By the way, baroque evolved from renaissance (means awakening), and idol was the antique.
Architecture NAZIs used was called neo-classicism combined with brutalism. Yes, brutalism is an own style of architecture. Soviets used to build in "soviet neo-classicism". Another architecture style in USSR was constructivism.