This January, however, the budding trend has faded, presumably because of her vital role in making the Cancún climate change conference a success. In contrast to years past, Espinosa is being hailed in the international media:
An essential goal in Cancun was for the parties to maintain sensible expectations and develop effective plans. That they met this challenge owes in good measure to the careful and methodical planning by the Mexican government, and to the tremendous skill of Mexican Foreign Minister Patricia Espinosa in presiding over the talks.
For example, at a critical moment she took note of objections from Bolivia and a few other leftist states, and then ruled that the support of the 193 other countries meant that consensus had been achieved and the Cancun Agreements had been adopted. She pointed out that “consensus does not mean unanimity.” Compare that with Copenhagen, where the Danish prime minister allowed objections by five small countries to derail the talks.
Mexico’s adept leadership also made sure smaller countries were able to contribute fully and join any meetings they wanted, avoiding the sense of exclusivity that alienated some parties in Copenhagen. That’s a sign that Mexico is one of the key “bridging states” that have credibility in both worlds. Another is South Korea. They will need to play key roles going forward.
(H/T) This from a piece on why Cancún was a success by Robert Stavins, a Harvard expert on climate agreements. I'm not qualified to properly place Espinosa in the broader context of Mexican history, but this seems quite likely to remain the crowning achievement of her tenure, and it's difficult to call to mind a more memorable and potentially significant performance on an international stage by a Mexican diplomat.
Update: Historian Michael Lettieri says in comments that Gilberto Bosques, who served in Vichy France, takes the cake.