The year 1939 was a pivotal one in the lead-up to ww1. explain some of the important events both at home and in europe that bring the world into war

Important events in Europe
Arguably, the most important event in Europe in 1939 was when Nazi Germany invaded Poland. This invasion directly violated a previous deal made by Germany, Great Britain, and France. As a result of this, Great Britain and France declared war on Germany in September of 1939.

Besides that invasion of Poland, the Soviet Union and Germany signed a non-aggression pact in 1939 as well. This was important for the time being, as it prevented Germany from having to fight a two front war.

Important events in the United States

The US passed the Neutrality Act of 1939. The goal in passing this law was to avoid being dragged into a foreign war. This law stopped America from trading arms with countries that were involved in a war.