We can never pressure other countries to do it unless we do it first.
In addition, regulating plastic means that for multi-national corporations the path of least resistance is to operate under the most restrictive standard instead of maintaining multiple packaging solutions.
You have no idea how consumer packaged goods supply chains work. And Chinese, Indian, and Nigerian policy makers are not going to care at all if we ban plastic soda bottles. And how high would this be on our list diplomatic priorities. Think about this for 4 seconds.
In addition, regulating plastic means that for multi-national corporations the path of least resistance is to operate under the most restrictive standard instead of maintaining multiple packaging solutions.