Why did roosevelt support a “europe first” strategy even though it was japan that had first attacked the united states?

FDR believed that the most immediate threat was posed by Nazi Germany under Adolf Hitler who had made several inroads in Europe since the war. the threat of Europe would spill over to America as Nazi Germany expansionism and supremacy agenda was very contagious.

After WW1 it took a while for life to go back to normal. Everyone around this time were creating new ideas and which lead to mass production. The demand for the multitude of new product was higher then ever and they thought that they were getting somewhere. However the prosperity of the 20s was not universal, many places were still dependent on farming. But everything went downhill and it led to the great depression