The head of Japan's biggest oil and gas producer has warned that Australia risks undermining global security through a decision to "quietly quit" the international gas trade. Key points: A gas company executive says Japan has been rattled by government interventions in Australia's gas industry A gas company executive says Japan has been rattled by government interventions in Australia's gas industry He says Russia, China and Iran will likely fill any void if Australia exits LNG production He says Russia, China and Iran will likely fill any void if Australia exits LNG production A Japanese ambassador says his country depends…