He did answer that on his blog however:
"It's true that this is a domestic solution to an international problem and that there's no U.S. regulation that will affect, say, an Asian-made product sold in South America, even though that product could still be used to take down U.S. websites. But the main costs in making software come from development. If the United States and perhaps a few other major markets implement strong Internet-security regulations on IoT devices, manufacturers will be forced to upgrade their security if they want to sell to those markets. And any improvements they make in their software will be available in their products wherever they are sold, simply because it makes no sense to maintain two different versions of the software. This is truly an area where the actions of a few countries can drive worldwide change."[0]
And I mostly agree with him. If major markets start require certification of security (maybe something like FCC and CE), the rest of the world will follow as they want to trade in these premium markets. Sure, it will not solve the problem overnight, but at least it could be made less severe.
0. https://www.schneier.com/blog/archives/2016/11/regulation_of...