Born in Breslau, in what is modern-day Poland, Bräuer entered service in the German foreign ministry in 1920. From 1928 to 1930 he was a member of the German Democratic Party. On 1 August 1935 he joined the Nazi Party. At the outbreak of World War II in September 1939, Bräuer was posted at the German embassy in Paris. Later that year, Bräuer was named as envoy to Norway, and served in Oslo beginning on November 14, 1939. Bräuer was Germany's representative in Norway at the time of Nazi Germany's invasion of Norway in April 1940.
Until the invasion, the official German foreign policy was to respect Norwegian neutrality, a line with which Bräuer is said to have agreed and worked toward. However, on the evening of April 8, 1940, the envoy received orders from Berlin — he was to be Hitler's representative and deliver a German ultimatum for the occupation of Norway to the Norwegian government the next morning.
The Norwegian government refused the German demands and left the capital as it became clear that Norway was becoming overrun with German troops. In the following days, Bräuer tried to convince the Norwegian government and King Haakon VII to capitulate and to name Vidkun Quisling as prime minister. The Norwegian government refused these demands and vowed to resist the German invasion as long as possible.
On April 16, 1940, Hitler recalled Bräuer from Oslo, deciding that the Norwegian resistance to the invasion dictated that the country be administered by a more authoritarian personality. Hitler named Josef Terboven — an enthusiastic Nazi — to assume the position of Reichskommissar for Norway. Terboven wielded near-dictatorial powers in Norway until war's end.
- Henrik O. Lunde. Hitler's Pre-Emptive War: The Battle for Norway 1940 Casemate Publishers, Nov 1, 2010. pg. 226