"The new rules to relax the arms export ban will enable East Asian economic power to work with friendly countries such as the United States in the future to develop and produce high-tech weapons such as fighter jets. In this way, Tokyo can save costs - a trend that the United States and Europe have been following for some time.
With the new rules, Japan can also provide equipment such as heavy construction machinery or protective vests to its armed forces involved in UN peacekeeping missions. Until now, such things were considered weapons."
nothing talks about a weapon development that is intended for export, but rather about joint development and protective weapons -
like I said ... if the doctrine changes you can ask your mean questions, brother...