Nazi Germany
The first (original) Nazi Party was in Germany, but the ideology, of imperialistic racist fascism (the lower-case "nazism" ideology, instead of just the original, upper-case "N" Nazi Party that was an example of it) can be in any country.

German racist-fascism or Nazism was organized by Hitler as anti-Jewish, anti-communist, and for a Thousand-Year Reich in which "Aryans" or purebred descendants of Adam and Eve in Genesis 3, would have control over the entire world, and there would be no descendants from the snake (Satan) in Genesis 3, which Hitler believed Jews to be.
The Slavic peoples in the Soviet Union would become enslaved to Aryans, and that land would be the main breeding ground or "Lebensraum" to expand the numbers of Aryans so that they could achieve further conquests, and he thought that the most difficult country for Germany to defeat would be America — but, that he and his fascist allies would first need to defeat all of Eurasia. Then, he would take on America. That was his plan, ever since 1919, and as of 1928, his Second Book, and it never changed.

Conquest of all lands, and extermination of all Jews, was to produce his Thousand-Year Reich, which he thought would be "Paradise." Nazism wasn't only about exterminating Jews. It was also, very importantly, about conquering the Soviet Union.

America's President Harry S. Truman came into office on 12 April 1945 fearing Stalin whom he didn't know, resenting his immediate predecessor FDR whom he had barely even met and did not like, and thinking that the best thing for America would be if the Germans and the Russians would simply kill each other off.

His chief aide, James Byrnes, and Britain's Winston Churchill, worked on him, to get him to fear Stalin, but it was Truman's personal hero, General Dwight Eisenhower, who sealed things that way in his mind, by telling Truman at the Potsdam Conference that if America would not defeat the Soviet Union, then the Soviet Union would defeat America; and, so, on 25 July 1945, Truman decided to start the Cold War, and he did it by telling Stalin that America would not allow the Soviet Union to have any control over its bordering nations which were being contested by the Soviets versus the Germans — in other words: that the Soviet Union must not interfere if the people in those countries might choose to ally with America against the Soviet Union, instead of with the Soviet Union against America.

His attitude toward Stalin, and toward the Soviet Union, suddenly became clearly hostile on that day — exactly the opposite of what FDR's had been. Thus, on 25 July 1945, Truman wrote from the Potsdam Conference in Berlin to his wife Bess in Washington,
"There are some things we can't agree to. Russia and Poland have gobbled up a big hunk of Germany and want Britain and us to agree. I have flatly refused. We have unalterably opposed the recognition of police governments in the Germany Axis countries. I told Stalin that until we had free access to those countries and our nationals had their property rights restored, so far as we were concerned there'd never be recognition. He seems to like it when I hit him with a hammer."
That's as-if if Stalin were to have told Truman that if the people in Mexico or in Canada were to ally with the Soviet Union against America, that would be okay. Stalin obviously could not agree to it; and this statement by Truman, that America had a right to ally with the USSR's adjoining countries against the USSR, did inevitably start the Cold War. If it felt to Stalin like Truman had just "hit him with a hammer," then practically anyone but the bigoted Truman would have understood why. It was mega-historic, a complete reversal of what FDR's attitude and policies had been, but 'historians' continue to ignore it, even to this day, because they don't want to acknowledge the historical fact that Truman started the Cold War, and that subsequent U.S. Presidents refused to put a stop to it, but instead continued to feed its flames.

Konrad Adenauer was chosen by Truman to lead post-War West Germany, because Adenauer was strongly supportive of America's conquering the Soviet Union but had no particular interest in Hitler's aim to eliminate Jews. He was a pan-Christian rabid anti-communist who viewed atheism with deep contempt and so founded the Christian Democratic Union and Christian Social Union Party, not only against communists but against all socialists, under the view that Germany's Social Democratic Party was too accommodationist to communists, and not sufficiently hostile toward the Soviet-controlled half of Germany, the GDR. He was the sort of person that Truman wanted to lead Western Germany.

Truman's CIA brought into America and other anti-Soviet countries thousands of 'former' Nazi officials and put them to work in intelligence, weapons-design, and other anti-Soviet services. Truman's Nuremberg Tribunals were show-trials of Hitlerites whom the Truman Government didn't need, and whom it displayed as sacrificial wolves to execute in order to fool the world to think that America wasn't going to simply take up where Hitler's regime had left off in trying to conquer the entire world in a battle against 'communism'. The idea was to play up the Nazis' anti-Jewish obsession and play down their anti-communist obsession, so that people wouldn't even notice that America had simply picked up Hitler's world conquest objective, but this time for America instead of for Germany.

On 10 January 2016, Muguel Auso headlined "Adolf Heusinger: the story of the Nazi general who ended up leading NATO" and accurately described the career of one of Hitler's leading and always loyal generals whom the Truman team not only excluded from the execution list but actually advanced into leadership positions not only in West Germany's military but then even to the very top of NATO as chairman of the NATO Military Committee - the highest rank in the organization's military branch. That article was republished by Ronald Ángel, on 28 June 2022, as "The story of the Nazi general who ended up becoming head of NATO: World War I veteran, Nazi army chief of operations, secret CIA agent, and chairman of the NATO military committee."

On 21 March 2022, Beatriz Talegón headlined "NATO and its links with Nazism: Some of the high commands of NATO came from being high military commands of German Nazism and very close to Adolf Hitler", and it became posted by Ronald Ángel on 23 June 2022. It summarily described 9 top Nazi generals whom the Truman regime not only let off the hook but promoted to high positions in NATO and in Germany's post-War military: Reinhard Gehlen, Adolf Heusinger, Hans Spiedel, Johannes Steinhoff, Johann von Kielmansegg, Ernst Ferber, Karl Schnell, Franz Joseph Schulze, and Ferdinand von Senger und Etterlin.

Germany — which has 231 U.S. military bases (and you can count each one of them on that list) — is a vassal-nation of the U.S. empire, and therefore cannot make any decision in international relations that the U.S. Government (the empire's headquarters) won't allow it to make. Germany's re-unification on 3 October 1990 turned Germany, a nation that the Soviet Union had defeated in World War Two as a consequence of Hitler's failed Operation Barbarossa invasion of the Soviet Union, into becoming, yet again, nazi, but this time under America's version of racist-fascism (nazism, the ideology), which wasn't entirely the same as Hitler's had been: it wasn't, at all, obsessed against Jews. It's obsessed, instead, only against Russians.

Post WW-II history has been systematically misrepresented as-if the aggressor were Russia. U.S.-and-'allied' nations pretend that America and Britain defeated Germany, but they only stole it after the Soviets had won it and won WW II. Instead of gratitude for that, Russia gets, from them, only lies against it. And, ever since 25 July 1945, when the Cold War started, the aggression between the two sides has always been by America against Russia, and it has also been aggression by America against China, and against any country that is on good terms with one or both of those. It is, in fact, the non-stop U.S. campaign to take over the entire world — control all international relations. This can end in only two ways: either by the U.S. regime's quitting its attempt, or else by global nuclear annihilation.
Investigative historian Eric Zuesse's new book, AMERICA'S EMPIRE OF EVIL: Hitler's Posthumous Victory, and Why the Social Sciences Need to Change, is about how America took over the world after World War II in order to enslave it to U.S.-and-allied billionaires. Their cartels extract the world's wealth by control of not only their 'news' media but the social 'sciences' — duping the public.