The Supreme Court ruled 6-3 in the case of Zivotofsky v. Kerry (remember?) that Congress is not within its prerogative to order the executive branch to recognize Jerusalem as “Jerusalem, Israel” on the passports of US citizens who are born there. Official US policy is and has been since 1948 that Jerusalem is an “international” city, so if you happen to be born there your birthplace will be officially listed on your passport as just “Jerusalem.” Congress passed a law in 2002 requiring the government to list it as “Jerusalem, Israel” instead, but the State Department has always (even under Bush) held that the law was an unconstitutional infringement on the executive’s right to conduct foreign policy. While Congress does have authority over the passport process, the court ruled, accurately in my view, that overruling the executive on a question like this would have de facto opened the door to Congress setting its own policies with respect to recognizing nations and dealing with international territorial disputes, when these are clear responsibilities of the executive, not the legislature. Imagine Congress suddenly deciding to recognize the Donbas as a separate nation, contrary to administration’s policies and you can see why this would be untenable.