The American hand was strengthened by the interception and decryption of the secret instructions of the Japanese government to its delegation. The message revealed the lowest navy report acceptable to Tokyo; U.S. negotiators have used this knowledge to push the Japanese. This success, one of the first in the U.S. government`s budding eavesdropping and cryptology efforts, ultimately led to the growth of these agencies.  It was natural for Japan to assume that, after convening the conference, the United States would be willing to pay a high price for success and could therefore commit to positively improving Japan`s political situation. The problem was to determine an objective of great maritime advantage for Japan, one that would require an unnecessary extension of the Japanese navy while respecting its political policy and a goal that could be achieved by intelligent diplomacy at the conference. Article XIX of the Treaty also prohibits Britain, Japan and the United States from building new fortifications or naval bases in the Pacific Ocean. Existing fortifications in Singapore, the Philippines and Hawaii could be preserved. This was an important victory for Japan, as the newly fortified British or American bases would be a serious problem for the Japanese in the event of a future war. This provision of the treaty essentially guaranteed that Japan would be the dominant power in the Western Pacific and was instrumental in Japan`s acceptance of the limits of shipbuilding.  Following the First World War, the leaders of the international community tried to prevent the possibility of a new war.
The rise of Japanese militarism and an international arms race have reinforced these concerns. As a result, policymakers have worked to reduce the growing threat. Senator William E. Borah (R-Idaho) has conducted a congress effort to demand that the United States involve its two main rivals in maritime arms racing, Japan and the United Kingdom, in disarmament negotiations. Being unpopular with much of the Imperial Japanese Navy and increasingly active and important ultranationalist groups, the value accepted by the Japanese government led to much mistrust and accusation among Japanese politicians and naval officers. [Citation required] Elihu Root, Henry Cabot Lodge and Oscar Underwood, the last to lead the Democratic minority in the Senate, were part of the U.S. delegation led by Secretary of State Charles Evans Hughes. The main objective of the conference was to curb Japanese naval expansion in western Pacific waters, particularly with regard to fortifications on islands of great strategic value. Its secondary objectives were to achieve a definitive limit on Japanese expansion and to allay fears of possible antagonism with the British. They should ease Anglo-American tensions by lifting the Anglo-Japanese alliance, agreeing on a favourable naval relationship with Japan and formally agreeing to the Japanese to pursue the open-door policy in China. Japanese officials focused more on the peculiarities than the British, and approached the conference with two main objectives: to sign a maritime treaty with Great Britain and the United States and to obtain official recognition of Japan`s special interests in Manchuria and Mongolia.