When U.S. citizens are killed by terrorists abroad, there's an understandable and entirely sympathetic urge to hold someone accountable.

But suing third parties with no direct involvement in the attacks—banks, social media providers, pharmaceutical companies, sovereign nations—is proving to be a stretch.

Two new decisions—both issued Friday in wins for White & Case partner Christopher Curran—make this point.

In a victory before the U.S. Court of Appeals for the Fourth Circuit, Curran got a $34 million judgment against Sudan in the bombing of the USS Cole reversed and remanded.

That same day, he also got a lawsuit in Manhattan federal court against Saudi Arabia banking giant Al Rajhi Bank dismissed with prejudice. That case stems from terrorist suicide bombings at three hotels in Amman, Jordan, in 2005.

Curran is on the short list of lawyers with the requisite expertise to handle such matters—he previously defended the Libyan government in multibillion-dollar U.S. litigation and negotiated a historic bilateral agreement to resolve the suits.

The Sudan case is especially interesting and may be bound for the U.S. Supreme Court because circuit splits don't come much cleaner than this.

Curran argued and lost a nearly identical case—same client, same plaintiffs, same amicus, same issue—before the Second Circuit in 2016.

Seventeen U.S. sailors were killed and 42 were injured when al-Qaida bombed the Cole at a port in Yemen on Oct. 12, 2000. Represented by Andrew Hall of Hall, Lamb, Hall & Leto in Miami, the victims or their families sued Sudan for providing material support for acts of terrorism.

Initially, Sudan did not mount a legal defense and was hit with a pair of default judgments—$315 million in 2012 and another $34 million in 2015.

That's when Sudan hired Curran and a White & Case team including partners Nicole Erb and Claire A. DeLelle in a bid to vacate the judgments.

In both appeals, Curran argued Sudan was not properly served. The plaintiffs simply mailed the documents, which were addressed to the Sudanese minister of foreign affairs, to the country's embassy on Massachusetts Avenue in Washington. Someone at the embassy accepted the envelope and signed the receipt.

The U.S. Court of Appeals for the Second Circuit in reviewing the $315 million penalty decided that method was good enough. (The case was before the Second Circuit because the plaintiffs were trying to enforce the judgment by collecting Sudanese funds from banks in New York.)

Sudan appealed the Second Circuit's decision to the U.S. Supreme Court, which has yet to grant or deny cert. In October, the high court asked the U.S. solicitor general to weigh in.

Now, the odds of cert are even higher under the strongly worded decision from the Fourth Circuit going squarely against its sister circuit.

“We find the Second Circuit's reasoning weak and unconvincing,” wrote Judge G. Steven Agee for the panel, with Judges J. Harvie Wilkinson III and Allyson Duncan concurring.

The panel concluded that the statute required the documents to be delivered to the Sudanese foreign minister in Sudan, not at the embassy.

Key to the decision: The U.S. government sided with Sudan as an amicus. In fact, the U.S. government refuses to accept service through mail or personal delivery to a U.S. embassy.

“Clearly, the United States cannot expect to receive treatment … that its own courts do not recognize in similar circumstances involving foreign states,” Agee wrote.

The panel also dinged the Second Circuit for claiming it afforded “great weight” to the State Department's views, only to summarily reject the department's position, “which seems to accord the State Department's view no weight at all. In contrast, the position we adopt in this case respects the 'great weight' the State Department's view merits,” Agee wrote in a surprisingly catty footnote.

In an interview, Curran said, “We are very pleased with the outcome at the Fourth Circuit and think it will strengthen our petition for cert from the Second Circuit's decision.”

In his other win Friday, Curran along with Erb and counsel Reuben J. Sequeria got Al Rajhi Bank off the hook in a suit by American victims of the hotel attacks in Jordan. The bank was sued along with HSBC, represented by Mayer Brown, for allegedly providing or facilitating banking services to al-Qaida and al-Qaida in Iraq.

But U.S. District Judge Denise Cote of the Southern District of New York found the court lacked jurisdiction.

“Allegations that a bank provides financial services to clients that associate with al-Qaeda, thereby aiding al-Qaeda, are 'not enough for personal jurisdiction purposes,” she wrote. “The plaintiffs have failed to connect Al Rajhi Bank to the November 9, 2005 attacks.”

Curran said, “These two cases together do illustrate a trend, in which bona fide victims of terror, through aggressive plaintiffs lawyers, seek to overreach and hold innocent companies or entities liable.”

He continued, “We're pleased in both instances that the courts applied legal principles resolving these matters.”

Hall wasn't impressed with the Justice Department amicus brief or the Fourth Circuit decision itself.

“When it's inconvenient , the Justice Department will say, 'Don't follow the exact language of the statute, but there are loads of other cases that say Congress knows what it's doing and the statute controls,” he said Thursday. ”The worst that can happen is we re-serve and do it again, but we think the Fourth is wrong.”