What is the main idea of this excerpt? "When the World War began in 1914, the President of the United States advised his fellow countrymen to remain neutral even in thought. When the armistice was signed in 1918, there were 21,000 new American millionaires, Du Pont stock had gone from $20 to $1,000 a share, and J. P. Morgan was said to have made more money in two year than the elder Morgan made in his entire life…

Between August 1914 and February 1917, more than $10,500,000,000 worth of goods were shipped out of America. Munitions played a prominent part in this traffic…There was only one cloud on the horizon: the war might end. Every time there was talk of peace, munitions stocks went down from 5 to 40 percent. War had brought prosperity, peace threatened to bring calamity.

Then, another nightmare began to trouble Wall Street. How were the Allies to pay for these goods? The credit of the Allies was virtually exhausted. The United States had grown from a debtor nation to one of the greatest creditors of the world… But this hour of darkness was also the beginning of the dawn. On April 6, 1917, the United States entered the conflict, and the heart-beats of the war traffickers became normal again. It is not contended here that the United States fought in the World War solely because of its armament makers and their financiers. There were many other factors in the situation… [But] American commitments with the Allies were so enormous that only our entry into the war saved the country from a major economic collapse.

In 1917 on the floor of Congress it was charged that as early as March 1915, the Morgan interests and organized and financed a huge propaganda machine, including 12 influential publishers and 197 newspapers, for the purpose of “persuading” the American people to join the Allies."