"The Nirvana Sutra declares, “If troubles are inflicted upon a sage, then the country where he dwells will be attacked by other countries.” And the Benevolent Kings Sutra states essentially the same thing. If I, Nichiren, am attacked, then from heaven and earth and the four directions, great calamities will pour down like rain, jet up like fountains, or come surging forward like waves. If the many priests, those hordes of locusts who afflict the nation, and the ministers in power in the government persist in their ever-increasing slanders and accusations against me, then great disasters will occur in growing magnitude.
When an asura demon tried to shoot at the god Shakra, his arrow rebounded and pierced him in the eye. And when the garuda birds attempted to attack the dragon king Anavatapta, flames erupted from their own bodies and consumed them. Is the votary who upholds the Lotus Sutra inferior to Shakra or the dragon king Anavatapta?" -- On Rebuking Slander and Eradicating Sins
From this it follows that the disasters befalling Japan are solely because Nichiren Daishonin is held in contempt by the Soka Gakkai, the Nichiren Shu, the Nichiren Shoshu, the modern day Kempon Hokke, the Pure Land sect, and the Japanese government.