10 U.S.C. § 434 — Reservation of defenses and immunities

This section protects the United States from accidentally losing its legal protections. When the government submits to judicial proceedings in a state or other legal jurisdiction - in connection with a commercial activity carried out under this subchapter - that act of submitting to the proceedings does not by itself count as a waiver. Specifically, it does not waive the "defenses and immunities of the United States," meaning the government keeps its normal legal defenses and its sovereign immunity protections even while participating in that court case.