The U.S. ambassador to Mexico faced a harsh choice as the release of secret cables made his job nearly impossible: Quit to rescue one of Washington's most strategic relationships or weather the storm to show that diplomats should not suffer for doing their jobs.
In the end, Carlos Pascual resigned, the first U.S. ambassador to lose his job over thousands of sensitive diplomatic cables released by the WikiLeaks website.
His frank cables detailing infighting and jealousies among Mexican security forces contrasted with public U.S. praise for Mexico's fight against drug trafficking. They deeply angered Mexican President Felipe Calderon, who repeatedly stated he could no longer trust the ambassador. Even opposition lawmakers say they became reluctant to meet with Pascual.
The crisis revealed the fine line President Obama's administration has had to walk between appeasing important allies and standing up for its diplomats. With potentially thousands more documents to be unveiled, the question is whether the outcome of the Mexico dilemma will set a precedent.
"Ambassador Pascual made a principled decision to resign because there were issues more important than him. It was self-sacrificing of him," said Andrew Selee, director of the Mexico Institute at the Washington-based Wilson Center.
Mexico is not the only country where leaked cables have deeply complicated the work of U.S. ambassadors.
The U.S. ambassador to Libya, Gene Cretz, was recalled to Washington in January after WikiLeaks posted his blunt assessment of Moammar Gadhafi's eccentricities.
For now, the WikiLeaks uproar has led to an ambassador's downfall only in Mexico.
That speaks to Mexico's unique relationship with the United States, one marked by more than two centuries of wars and mistrust -- but also one of mutual fascination and dependence. A 2,000-mile border, decades of immigration and trade and the shared problem of drug trafficking makes Mexico a prickly but indispensable U.S. ally.
Neither country can easily dismiss the other's concerns or allow relations to freeze, even if it sometimes means swallowing national pride.
So far, Pascual's resignation has caused little public reaction in Washington, overshadowed by the upheaval in the Middle East. But that could change during Senate confirmation hearings for a new ambassador, experts said.