It's the "If I could speak, you would understand" incident... "If I could speak, you would understand" was Prime Minister Inukai Tsuyoshi's last words after he was shot in the attempted coup d'état on May 15th, 1932.
Inukai may die, but liberty never will... The correct quote is "Itagaki may die, but liberty never will!", a phrase Itagaki Taisuke shouted after he narrowly survived an assassination attempt at Chukyo-in Shrine in 1882.