I’m confused as to why they have to register at all.
The Foreign Agents Registration Act (FARA) was enacted in 1938. FARA is a disclosure statute that requires persons acting as agents of foreign principals in a political or quasi-political capacity to make periodic public disclosure of their relationship with the foreign principal, as well as activities, receipts and disbursements in support of those activities. Disclosure of the required information facilitates evaluation by the government and the American people of the statements and activities of such persons in light of their function as foreign agents. The FARA Registration Unit of the Counterintelligence and Export Control Section (CES) in the National Security Division (NSD) is responsible for the administration and enforcement of the Act.