I really think the only reason this is being implemented is to save them the trouble of having two screening checkpoints for passengers headed to the insane countries.

If they really thought there was a threat, they would have (1) done this much sooner, and (2) be instituting the policy for domestic flights as well. Unfortunately, seeing as these are the Japanese, they will likely do a much "better" job enforcing this policy than the morons at the TSA, and therefore it will be much harder to sneak things through security.