The United States should have entered the war. It makes sense on multiple levels. From a political standpoint, the United States said it would get involved if the Germans used unrestricted submarine warfare. If the U.S. had backed down after making this statement, it would not have looked good for the government of the country. There was also an economic reason to get involved in the war. The United States had loaned billions of dollars to the Allies. If Germany was able to defeat the allies, that investment would have been completely lost. Also, the United States was making money on all of the military products that they were shipping to the front. These factors make it necessary for U.S. entry in to World War I.