From the earliest days, it has been an accepted article of faith that every aircraft flying outside its own country should carry some guarantee of its safety, conforming to an international standard, if not controlled internationally. No aim has been more assiduously pursued. But, after nearly forty years of the international regulation of aviation, there is no international standard of airworthiness with which aircraft are compelled to comply. The questions that now arise are whether the objective is ever likely to be achieved, and whether, in fact, international standards are necessary to safety.