By the end of 1940, Adolf Hitler had reached the pinnacle of his power as the leader of Nazi Germany. Several factors contributed to this consolidation of power, which allowed him to dominate not only Germany but also exert significant influence over other countries.

1. Military Successes:
One of the key reasons for Hitler's rise to power was his military successes. In 1940, Germany had already conquered and occupied several countries, including Poland, Denmark, Norway, Belgium, the Netherlands, and France. These victories solidified Hitler's reputation as a formidable military leader and boosted his popularity among the German people.

2. Consolidation of Political Power:
Hitler effectively consolidated his political power within Germany, ensuring that he had complete control over the government and its institutions. He eliminated opposition parties, banned trade unions, and suppressed dissent through the establishment of the Gestapo, the secret police. This allowed him to rule with an iron fist and maintain a tight grip on the country's political affairs.

3. Propaganda and Indoctrination:
Hitler and the Nazi regime were masters of propaganda and indoctrination. Through the use of mass media, rallies, and public speeches, Hitler was able to shape public opinion and manipulate the German population. Propaganda campaigns portrayed Hitler as a charismatic and visionary leader, creating a cult of personality around him. This enabled him to maintain support and loyalty from the German people.

4. Economic Recovery:
Hitler's policies aimed at reviving the German economy proved successful in the early years of his rule. Unemployment rates decreased, and public works projects were undertaken to stimulate economic growth. This economic recovery helped to solidify Hitler's popularity among the German population, as many attributed their improved standard of living to his leadership.

5. International Appeasement:
During this period, Hitler also benefited from the policy of appeasement pursued by major European powers, such as Britain and France. These countries were reluctant to confront Hitler's aggressive expansionist policies, instead choosing to negotiate and make concessions to avoid a conflict. This allowed Hitler to continue his territorial ambitions without significant opposition.

6. Lack of Effective Opposition:
By the end of 1940, Hitler had successfully eliminated or neutralized any significant opposition within Germany. The Night of the Long Knives in 1934, where Hitler purged his own party of dissenters, and the subsequent loyalty oath from the military solidified his control. Additionally, Hitler's propaganda machine effectively depicted any dissenters or critics as enemies of the state, further quelling opposition.

In conclusion, by the end of 1940, Hitler had reached the pinnacle of his power due to his military successes, consolidation of political power, effective propaganda and indoctrination, economic recovery, international appeasement, and the elimination of opposition. This allowed him to dominate Germany and exert significant influence over other countries, setting the stage for further aggression and eventually leading to World War II.