After the collapse of the administration of Tanaka Giichi in June 1929, Hamaguchi was selected to become Prime Minister of Japan and formed a cabinet based largely on Minseitō party members, which supported domestic economic reforms over overseas military adventurism. With a strong sense of his own rectitude and a tough, stubborn temperament, Hamaguchi inspired trust, promising that he was "ready to die if necessary" for the good of the country during his inaugural speech and promising an administration free of corruption. Hamaguchi's primary concern was the Japanese economy, which had been in an ever-increasing recession since the end of World War I, and had been greatly weakened by the devastation caused by the 1923 Great Kantō earthquake. Hamaguchi promoted retrenchment, deflation and the rationalization of industry. The 1929 Great Depression, starting soon after he took office, put further pressure on the economy. Initial public confidence and strong support from Emperor Hirohito and his entourage, including the "genrō" Saionji Kinmochi allowed Hamaguchi to implement fiscal austerity measures, which included ratification of the London Naval Treaty of 1930, which curtailed military spending. However, his measures to help stimulate exports, such as maintaining the Japanese yen on the gold standard, proved disastrous. The failure of Hamaguchi's economic policies played into the hands of right-wing elements, already enraged by the government's conciliatory foreign policies and Japan’s increasing unemployment problems. The opposition "Rikken Seiyūkai" joined forces with the vocal anti-Treaty faction within the Imperial Japanese Navy to accuse Hamaguchi of infringing of the military's "right of supreme command" as guaranteed under the Meiji Constitution. Hamaguchi's initial popularity quickly waned, and he fell victim to an assassination attempt on 14 November 1930 when he was shot inside Tokyo Station by Tomeo Sagoya, a member of the "Aikokusha" ultranationalist secret society. (Nine years earlier another Prime Minister, Hara Takashi, had been assassinated near the same place.) The head of the "Aikoku-sha" was "Seiyūkai" politician Ogawa Heikichi. The wounds kept Hamaguchi hospitalized for several months. Hamaguchi was reelected to a second term as Prime Minister of Japan in March 1931. However, with his health continuing to deteriorate, he was unable to attend the 59th Session of the Imperial Diet, which opened with Foreign Minister Kijūrō Shidehara as acting Prime Minister.