Requests for provision of counsel and payment of expenses in civil cases may be granted in trial and appellate proceedings in either of the following civil cases:

(a) Where the act complained of occurred in the performance of official duty; or

(b) Where the case is considered to have a significant impact upon the relations of US forces with the host country or is considered to involve any other particular US interest. No funds shall be provided under this part in cases where the United States of America is in legal effect the defendant, without prior authorization of the Judge Advocate General.