As the German foreign minister (1897-1900) and chancellor (1900-09), he advocated for an aggressive, militaristic foreign policy. His Weltpolitik was dedicated to the creation of a German Empire through military force.
Theobald von Benthmann-Hollweg:
As an advocate for war in 1914, he realised a programme of territorial expansion (Poland was to be ethnically cleansed to provide living space for German settlers).
First Reich: Holy Roman Empire of Charlemagne 800-1806
Second Reich: German Empire founded in 1871 by Bismark after Prussia defeated France
Both had gained land, kept it throughout the war and fought to have alliances, similar to Hitler's foreign policy.
Hitler stated in Mein Kampf (1925) his want to:
Expand and maintain the purity of the Aryan race
Overturn the Treaty of Versailles (and land loss)
Expand into Russia territory (and destroy the communist threat)
Eliminate the Jewish threat
Create Lebensraum (living space) in the east
Hitler set out his 'stufenplan' stage plan:
The Treaty of Versailles to be broken
War with Britain and France
War with the Soviet Union
(within his secret 2nd book) Dominate the USA
Disarmament Conference 1933:
This conference was called to discuss the revision of the Treaty of Versailles to allow Germany to increase armaments. However, France refused to let Germany to have equal forces with them, resulting in Hitler leaving the conference and abandoning the negotiations. This made Germany appear to be the victim and meant no agreements were made to limit the German armed forces.
Non-Aggression Pact with Poland 1934:
This gave Poland the impression that Hitler had no intention of invading them at least until 1944, due to it being a 10 year pact.
Saar:
As part of Germany temporarily taken due to the Treaty of Versailles, the people of the Saar did a plebiscite in 1935, in order to decide who they should belong to. The Nazis launched a propaganda campaign and over 90% voted to re-join Germany.
During March 1935, Hitler announced the existence of the German Luftwaffe and conscription for the German Army, breaking the Treaty of Versailles.
Anglo-German Naval Agreement 1935:
This agreement between Germany and Britain agreed that Germany could build a navy 35% the size of Britain's surface fleet, and 100% the size of their submarine fleet. Britain agreed to this as they wanted to reduce tensions with Germany, however it weakened the Stresa Front (an agreement between Italy, Britain and France) which was dedicated to reducing German militarism and expansionism. Therefore, France was furious at Britain.
Abyssinian Crisis 1935:
In 1935, Italy invaded the African tribal nation Abyssinia in a brutal way, by using chemical weapons like poison gas. The League of Nations condemned the attack, but were powerless to stop. Their ineffectuality was clear when they imposed economic sanctions on Italy, not including vital materials like oil, coal, iron and steel.
Remilitarising the Rhineland 1936:
While the League of Nations was busy with the Abyssinian crisis, Hitler ordered troops into the Rhineland, breaking the Treaty of Versailles. This was risky and Hitler was advised by German generals that troops would have to withdraw if the French intervened. But, Hitler gambled that the French wouldn't risk a negative response to any military action against German troops on German soil, which was correct as there was no French reaction.
(1) Anschluss (March 1938):
Hitler hoped to achieve Anschluss without bloodshed, so the Austrian government, heavily pressured by Austrian Nazis, signed a deal with Germany that was one-sided, in favour of Germany. Without Hitler's knowledge, the Austrian chancellor, Schuschnigg, announced plans to hold a plebiscite to decide Austria's future, which caused Hitler to pressure him into resigning. However, they refused to replace him with a Nazi chancellor, causing Hitler to send in troops.
(2) Anschluss (March 1938):
As Hitler drove through the streets of Austria, the people chanted 'One Reich, One People, One Fuhrer', as Hitler was seen as their hero. Hitler had been nervous about Anschluss, as he originally only wanted a closer political alliance, but once he saw the ecstatic acclaim of Austrian people did he decide on full Anschluss.
(1) The Sudeten Crisis:
Due to the Treaty of Versailles, 3 million Germans were living in Czechoslovakia, in an area called to Sudetenland. Hitler wanted this land. Chamberlain flew to Germany on the 15th and 22nd of September, in hopes of compromising with Hitler. This led to a conference at Munich, attended by Italy, Britain, France and Germany.
(2) The Sudeten Crisis:
However, on the 29th of September, Goering and Mussolini came to a compromise without Hitler, called the Munich Agreement, where the Sudetenland would be returned to Germany, as long as Hitler agreed to respect the territorial integrity of the rest of Czechoslovakia. Hitler was angry at this as he believed "they have robbed me of my war".
Czechoslovakia March 1939:
Only a few months later, Hitler broke the Munich Agreement and entered Czechoslovakia, which was a key turning point. This was because no argument on the grounds of self-determination could be made, as the territory had no German majority and had never been part of Germany. It was therefore an invasion.