How might regulators (governments) and operators (airlines and airport
owners) better coordinate the implementation of international
standards and national and local aviation security programs?

The biggest improvement, IMHO would be to profile = 100% screening of
persons who look like a terrorist or other criminal and spot check the
rest of the people entering airports. The cost of a therough check of
everyone is very high in terms of delays and lost customers. It might
be appropriate for everyone in the terminal to have authority to ask
to see ID and report suspicious persons to a hot line.   Neil