Actually - correcting myself. There IS a clause that unbans TikTok on ownership transfer. I didn't read far enough down:

> Section 4. Contingent voidness. [This act] is void if tiktok is acquired by or sold to a company that is not incorporated in any other country designated as a foreign adversary in 15 C.F.R. 7.4 at the time tiktok is sold or acquired.

If TikTok is transferred to a company not owned by China the act goes away.

So they could just do that, then reacquire the company and this law vanishes in a puff of logic.

The law would still be on the books. Presumably it would become non-void, and immediately active, if a Chinese company repurchased TikTok from a non-Chinese company. Much like unconstitutional laws prohibiting abortion became immediately active again after the recent Supreme Court ruling.

As I understand it, nope. States can't negotiate treaties on the US' behalf. Commerce and sanctions would fall under that as I understand it.

States also can't regulate interstate trade, which I believe trying to penalize Apple and Google would constitute, since neither has a office in Montana.

Couldn't it target the shops and companies that sell devices with Apple/Google app stores on them, instead?

Why can California require auto manufacturers to comply with their emissions standards if it is in effect regulating interstate trade?

California doesn't require auto manufacturers to do anything. They require dealers and individuals to only buy cars that meet said emissions standards, on penalty of refusing to allow them to be registered to be driven on the state's roads.

Yes there is. It's right there in section 4.