The United States is not a party to the Rome Statute, the treaty that established the International Criminal Court (ICC). By imposing sanctions on ICC personnel, the US asserts that domestic sovereignty overrides international mandates. This is a power move, not a legal argument.
Other non-member superpowers, specifically Russia and China, observe these tactics. Such penalties provide a political blueprint. If the world's largest economy can harass prosecutors to halt an investigation, other nations will likely adopt the same strategy to protect their generals or political leaders from war crimes charges.
This creates a two-tier system of justice. Smaller nations remain vulnerable to the court's reach, while global powers operate with impunity. The ICC loses its claim to universality when the most powerful states treat its warrants as optional suggestions or threats to be countered with economic warfare. The result is a legal vacuum where accountability depends on a country's GDP rather than the evidence of its crimes.