Rex Tillerson, former U.S. Secretary of State

Although former Exxon big boss Tillerson's stint as U.S. Secretary of State was the shortest for a president's first pick since the William McKinley administration, one long-running airline dispute did see a resolution under his watch. For now, at least. Shortly after Tillerson's appointment in 2017, the CEOs of American, Delta and United all implored him to review Open Skies agreements with Qatar and United Arab Emirates, based on allegations that those airlines were operating on government subsidies, a violation of those agreements. This was an argument the U.S. carriers and their allies have presented—and that the Gulf carriers have denied—since 2015. About a year later, Tillerson announced a deal with Qatar in which Qatar Airways promised to disclose financial statements meeting internationally recognized standards and averring they had no plans to add fifth freedom flights, meaning flights that both originate and end outside the carrier's country. A similar agreement with the United Arab Emirates was announced a few months later, albeit after Tillerson's departure. The binding level of the fifth freedom promises depended upon whom you asked, but it was enough for the U.S. Big Three to claim satisfaction and a victory.

That satisfaction might be temporary. A recent analysis piece by the CAPA Centre for Aviation noted, "The recent agreements appear to have been a brief truce, and the rhetoric could ratchet up at any time." Already, the Big Three U.S. carriers have raised objections over Air Italy growing its network from Milan to both San Francisco and Los Angeles next year, saying they are de facto fifth freedom flights, given Qatar's 49 percent stake in Air Italy.

In 2015, during an interview on CNN about Open Skies, then-Delta CEO Richard Anderson referenced the fact that many of the Sept. 11 hijackers came from the Arabian Peninsula, and in 2017, Qatar Airways CEO Akbar Al Baker made derogatory comments on the age of U.S. carriers' flight attendants, saying, "You're always being served by grandmothers on American carriers." Given all that heat, even the temporary cooldown Tillerson engineered is no small accomplishment.