Persian Gulf Tanker Attack: Iran Guilty? False Flag? Cui Bono?

Just as the prime minister of Japan was in an historic visit to Iran (the first since the 1979 revolution), a Japanese-owned tanker (and one other) was attacked in the Persian Gulf. US neocons are pointing the finger at Iran. Does it make sense to attack Japan in the midst of productive talks? Will the propaganda machine ramp up war talk?