Sara Nelson just can't help herself from being the star of the show in every single matter, can she?
I think as a regulatory issue, given that air crews cross multiple time zones, work in multiple states and countries even in a single day, that this authority rightly belongs with the FAA and not individual states.
Given that foreign aircraft are considered foreign soils, how can CA have jurisdiction on the work rules?
Foreign aircraft are not considered "foreign soils". Don't know where this myth originated. When an airline receives authority to operate to another country, they have to abide by certain regulations and procedures set forth by the destination country as well. From a law enforcement perspective, when the aircraft is on the ground in another country, the aircraft and its occupants are fully subject to the laws of that country, unlike, for example, the grounds of an Embassy or Consulate. A person cannot claim sanctuary on a foreign registered aircraft as they could inside an Embassy or Consulate (e.g. Julian Assange claiming sanctuary inside the Ecuadorian Embassy in London).
I have flown internationally as a captain for a few different airlines in my career, in the United States, China, and in Europe. Not once have I ever seen anything in any manual, ops specs, or regulation that states my aircraft is considered "foreign soil". In fact just the opposite, it states that I am required to comply with all applicable
laws and regulations of the country in which I operate. The FAA also makes it clear in 91.703 that U.S. registered aircraft "When within a foreign country, comply with the regulations relating to the flight and maneuver of aircraft there in force;". Typically, as in I have never seen an exemption to this, duty, flight time limitations, and rest requirements, are always left to the determination of the regulations of the State of Operator. However it is totally within reason that if a country were to decide that such regulations were inadequate, they could require additional crew in order for authorization to conduct regular operations to that country.
As a side note, another common false myth is that when you go through U.S. pre-clearance passport control in a foreign country, that you are then considered to be on U.S. soil. This is not true either. You are still fully on the soil of the departing country, and fully subject to their jurisdiction and laws. You are just in a secure area reserved for people who have received pre-departure clearance to enter the United States.