Because

- they issued a non-revocable arrest warrant for Netanyahu

- Afghanistan is a member and once threatened to prosecute US military staff for human rights violations.

Its not just the Trump adminstration, the "Hague Invasion Act" (https://en.wikipedia.org/wiki/American_Service-Members%27_Pr...) was signed into American law in 2002 by G.W. Bush.

Impunity is a drug.