Why did roosevelt take on unneutral step after another to assist britain and the soviet union in 1941

because of the invasion of pearl harbor on december 7th 1941 the japanese sent several planes to attack the u. s. warships in pearl harbor and it was a very bad attack a lot of people lost their lives the U. S was outraged with the japanese so the nest day on the 8th the U. S. declared war on japan and so began the begenning of ww2 for the united states