United States against Germany, April 6, 1917.
United States against Austria-Hungary, Dec. 7, 1917.
SEVERANCE OF DIPLOMATIC RELATIONS
The Nations that formally severed relations whether afterward declaring war or not, are as follows:
Austria against Japan, Aug. 26, 1914.
Austria against Portugal, March 16, 1916.
Austria against Serbia, July 26, 1914.
Austria against United States, April 8, 1917.
Bolivia against Germany, April 14, 1917.
Brazil against Germany, April 11, 1917.