If it decides on this case in the affirmative, the US Supreme Court would violate USA’s obligations under international law. The final status of Jerusalem cannot - and must not - be determined by a Congress law. Any law that does so, is in contravention with international law, and hence must be rescinded.
It is worth adding that the controversial Congress law further infringes the US Constitution, namely Article III, section 2, thereof.
Therefore, three steps must be taken at the US level:
- US Supreme Court must dismiss the case;
- US Supreme Court must declare Congress law illegal; and
- Congress must rescind its law.