How did the United States gradually awaken to the threat of totalitarian aggression in the late 1930 while still attempting to avoid entanglements?

As the 1930s progressed, the United States became aware of the growing threat of totalitarianism in Europe and in Asia. However, the United States still tried to avoid getting too involved in world affairs. In 1937, after Japan invaded China, President Roosevelt warned the nation about the growing threat of Axis expansion when he gave the “Quarantine Speech.” He told the people that the United States needed to be alert to the spread of aggressive actions in Europe and in Asia.
The United States had passed strict neutrality laws in the 1930s to prevent the country from getting dragged into another conflict similar like World War I. However, by the end of the 1930s and into the early 1940s, Congress began to make some modifications to the neutrality laws of the United States. The Neutrality Act of 1939 allowed the sale of war materials to countries at war on a cash and carry basis. The Lend-Lease Act said the United States would lend or lease weapons to Great Britain. The Destroyers for Bases program was developed allowing the United States to give destroyers to Great Britain in return for the right to build military bases in areas controlled by Great Britain. The creation of a hemispheric defense zone allowed the United States to patrol the western Atlantic Ocean, which allowed the United States to help the British locate German submarines.
These actions showed that the United States was alarmed by the actions of Germany, Japan, and Italy. While these actions showed the United States favored Great Britain, they also didn’t commit the country to join the war.
http://www.bbc.co.uk/history/ww2peopleswar/timeline/factfiles/nonflash/a1138420.shtml

https://www.ourdocuments.gov/doc.php?flash=false&doc=71