On October 12, 2000, Al Qaeda bombed the U.S.S. Cole, as it was refueling in the Port of Aden in Yemen. Seventeen American sailors were killed, and forty-two more were injured. Ps, family members of the deceased sailors, filed a complaint against D in the United States District Court for the Eastern District of Virginia. The Foreign Sovereign Immunity Act (FSIA) authorizes suits against a foreign state that has provided material support for certain acts of terrorism. The terrorism exception gave federal courts jurisdiction over the foreign state, but any claims had to be grounded in another substantive area of the law. Ps substantive claims rested on violations of the Death on the High Seas Act. D did not enter appearances or otherwise defend the suit. The district court held that D was liable and awarded compensatory damages. Congress passed the National Defense Authorization Act for Fiscal Year 2008 (NDAA) which repealed the prior FSIA terrorism exception to foreign state immunity, reenacted the exception's immunity-stripping language, and created a new substantive cause of action under the FSIA that authorizes recovery of noneconomic damages, including solatium and punitive damages. On remand, Ps sought leave to supplement their complaint to include a claim for noneconomic damages. The district court denied the motion. Ps and four new plaintiffs filed 'a new, related action pursuant to 28 U.S.C. § 1605A. In an effort to effectuate service of process pursuant to 28 U.S.C. § 1608(a)(3), the clerk of court sent the requisite documents 'via certified mail, return receipt requested,' to the embassy of D in Washington, D.C. Someone at the embassy accepted the envelope and signed the certified mail receipt. D did not enter an appearance or file any responsive pleadings. Ps moved for entry of default. The district court entered separate default judgment orders collectively awarding over $20 million in solatium and approximately $14 million in punitive damages to Ps. Thirty days after entry of those orders, D entered an appearance and moved to vacate the default judgments under Federal Rules of Civil Procedure 55(c) and 60(b). The district court denied the motion to vacate. D appealed. D contends the district court lacked personal jurisdiction over it because Ps did not properly effectuate service of process as required under the FSIA. D contends that mailing service to the Sudanese embassy in Washington, D.C., does not satisfy 28 U.S.C. § 1608(a)(3) and contravenes the 1961 Vienna Convention on Diplomatic Relations and Optional Protocol on Disputes.