What events lead to the U. S. deciding to enter WWI?

The United States later declared war on German ally Austria-Hungary on December 7, 1917. Germany's resumption of submarine attacks on passenger and merchant ships in 1917 became the primary motivation behind Wilson's decision to lead the United States into World War I.

a big one is

to appoint and regulate officers of the land and naval forces,

which caused much controversy ending the articles