DOJ can pressure Visa, Mastercard and Amex to stop processing payments for Apple. Due to how the international payments systems work, that's a global sanction, even if Apple had no footprint in US.
And before you claim that's absurd and impossible, there is precedent for US doing just that.[0]
> DOJ can pressure Visa, Mastercard and Amex to stop processing payments for Apple.
I think they'll find there's a world of difference in public support for "people leaking classified documents" vs "the people who make you and your family's phones, tablets, laptops, and watches".
And before you claim that's absurd and impossible, there is precedent for US doing just that.[0]
EDIT: There is also an earlier precedent, UIGEA - https://en.wikipedia.org/wiki/Unlawful_Internet_Gambling_Enf...
0: https://www.cnet.com/tech/services-and-software/credit-card-... (yes, the blockade was lifted later but my point was that the nuclear option is available)