History

National Socialist philosophy came together at a critical time for Germany; the nation had lost World War I in 1918, but had also been forced to sign the Treaty of Versailles, an intentionally devastating capitulation, and was in the midst of a period of great economic depression and instability. The Dolchstosslegende, or "stab in the back" described by the National Socialists featured a claim that the war effort was sabotaged internally, in large part by Germany's Jews. The National Socialists suggested that a lack of patriotism had led to Germany's defeat (for one, the front line was off of German soil at the time of the armistice). In politics, criticism was directed at the Social Democrats and the Weimar government (Deutsches Reich 1919-1933), which the National Socialists accused of selling out the country. The concept of Dolchstosslegende led many to look at Jews and other so-called "non-Germans" living in Germany as having extra-national loyalties, thereby raising antisemitic sentiments and the Judenfrage (German for the "Jewish Question"), at a time when the Völkisch movement and a desire to create a Greater Germany were strong.
Although Adolf Hitler had joined the Nazi Party in September 1919, and published Mein Kampf in 1925 and 1926, the seminal ideas of National Socialism had their roots in groups and individuals of decades past. These include the Völkisch movement and its religious-occult counterpart, Ariosophy. Among the various Ariosophic lodge-like groups, only the Thule Society is directly related to the origins of the Nazi party.
The term Nazism refers to the ideology of the National Socialist German Workers Party and its Weltanschauung, which permeated German society (and to some degree European and American society) during the party's years as the German government (1933 to 1945). Free elections in 1932 under Germany's Weimar Republic made the NSDAP the largest parliamentary faction; no similar party in any country at that time had achieved comparable electoral success. Hitler's January 30, 1933 appointment as Chancellor of Germany and his subsequent consolidation of dictatorial power, marked the beginning of Nazi Germany. During its first year in power, the NSDAP announced the Tausendjähriges Reich ("Thousand Years' Empire") or Drittes Reich ("Third Reich", a putative successor to the Holy Roman Empire and the German Empire).

Post-1933 developments
The British Conservative party and the right-wing parties in France appeased the Nazi regime in the mid- and late-1930s, even though they had begun to criticise its totalitarianism and in Britain especially, Nazi Germany's policies towards the Jews; however, Britain (from 1931 onwards under an overwhelmingly Conservative government) had appeased pre-Nazi Germany. Important reasons behind this appeasement included, first, the erroneous assumption that Hitler had no desire to precipitate another world war, even though in Mein Kampf Hitler explained the party's program to the voters in detail, describing World War I very much as he actually fought it, overtly and explicitly committing himself to World War II in precise detail, and second, when the rebirth of the German military could no longer be ignored, a concern that neither Britain nor France was yet ready to fight an all-out war against Germany.
The second excuse, that the West was not ready for war with Germany is, as Churchill pointed out, unsatisfactory, for the appeasement program worsened that problem, for example by removing Czechoslovakia's resources from the anti Nazi side, and adding them to the Nazi side. As Churchill said of appeasement:
"You were given the choice between war and dishonor. You chose dishonor, and you will have war."
"If you will not fight for the right when you can easily win without bloodshed; if you will not fight when your victory will be sure and not too costly; you may come to the moment when you will have to fight with all the odds are against you and only a precarious chance of survival. There may even be a worse case. You may have to fight when there is no hope of victory, because it is better to perish than live as slaves."
In 1936, Nazi Germany and Japan entered into the Anti-Comintern Pact, aimed directly at countering Soviet foreign policy. This alliance later became the basis for the Tripartite Pact with Italy, the foundation of the Axis Powers. The three nations united in their rabid opposition to communism, as well as their militaristic, racist regimes, but they failed to coordinate their military efforts effectively.
In his early years, Hitler also greatly admired the United States of America. In Mein Kampf, he praised the United States for its race-based anti-immigration laws and for the subordination of the "inferior" black population. According to Hitler, America was a successful nation because it kept itself "pure" of "lesser races". Nevertheless, his view of the United States became more negative as time passed.
The Nazi regime in Germany ended with World War II in 1945, when the party was declared a criminal organisation by the victorious Allied Powers. Since 1945, Nazism has been outlawed as a political ideology in Germany, as are forms of iconography and propaganda from the Nazi era. Nevertheless, neo-Nazis continue to operate in Germany and several other countries. Following World War II and the Holocaust, the term Nazi and symbols associated with Nazism (such as the Swastika) acquired extremely negative connotations in Europe and North America.