The country declaring war is named first.
Austria--Belgium, Aug. 28, 1914.
Austria--Japan, Aug. 27, 1914.
Austria--Montenegro, Aug. 9, 1914.
Austria--Russia, Aug. 6, 1914.
Austria--Serbia, July 28, 1914.
Brazil--Germany, Oct. 26, 1917.
Bulgaria--Serbia, Oct. 14, 1915.
China--Austria, Aug. 14, 1917.
China--Germany, Aug. 14, 1917.
Cuba--Germany, April 7, 1917.
France--Austria, Aug. 13, 1914.
France--Bulgaria, Oct. 16, 1915.
France--Germany, Aug. 3, 1914.
France--Turkey, Nov. 5, 1914.
Germany--Belgium, Aug. 4, 1914.
Germany--France, Aug. 3, 1914.
Germany--Portugal, March 9, 1916.
Germany--Rumania, Sept. 14, 1916.
Germany--Russia, Aug. 1, 1914.
Great Britain--Austria, Aug. 13, 1914.
Great Britain--Bulgaria, Oct. 15, 1915.
Great Britain--Germany, Aug. 4, 1914.
Great Britain--Turkey, Nov. 5, 1914.
Greece--Bulgaria, Nov. 28, 1916. (Provisional Government.)
Greece--Bulgaria, July 2, 1917. (Government of Alexander.)
Greece--Germany, Nov. 28, 1916. (Provisional Government.)
Greece--Germany, July 2, 1917. (Government of Alexander.)
Italy--Austria, May 24, 1915.
Italy--Bulgaria, Oct. 19, 1915.
Italy--Germany, Aug. 28, 1916.
Italy--Turkey, Aug. 21, 1915.
Japan--Germany, Aug. 28, 1914.
Liberia--Germany, Aug. 4, 1917.
Montenegro--Austria, Aug. 8, 1914.
Montenegro--Germany, Aug. 9, 1914.
Panama--Germany, April 7, 1917.
Panama--Austria, Dec. 10, 1917.
Portugal--Germany, Nov. 23, 1914. (Resolutions passed authorizing
military intervention as ally of England.)
Portugal--Germany, May 19, 1915. (Military aid granted.)
Rumania--Austria, Aug. 27, 1916. (Allies of Austria also consider
it a declaration.)
Russia--Bulgaria, Oct. 19, 1915.
Russia--Turkey, Nov. 3, 1914.
San Marino--Austria, May 24, 1915.
Serbia--Bulgaria, Oct. 16, 1915.
Serbia--Germany, Aug. 6, 1914.
Serbia--Turkey, Dec. 2, 1914.
Siam--Austria, July 22, 1917.
Siam--Germany, July 22, 1917.
Turkey--Allies, Nov. 23, 1914.
Turkey--Rumania, Aug. 29, 1916.
United States--Austria-Hungary, Dec. 7, 1917.
United States--Germany, April 6, 1917.