Now the Obama administration plans to close the separate, free-standing embassy building that has long served the U.S. Mission to the Holy See and move its functions into surplus office space in the compound of the U.S. Embassy to Italy late next year or early 2015. This would be a colossal mistake. Since news reports of the plan emerged in recent weeks, many have seen the move as a deliberate slap at the Catholic Church and the pope; some may even detect veiled anti-Catholicism. But whatever the administration's motivation, any such move to degrade the U.S. Embassy to the Holy See is not in America's best interests.
 
Since purchasing an office building next to the U.S. Embassy to Italy 10 years ago, the State Department has made several attempts to shut down the offices of the Mission to the Holy See and move them there, often attempting to justify the effort in budgetary terms. To this penny-wise/pound-foolish approach, the Obama administration has now added alleged post-Benghazi security concerns, which it claims require consolidation of U.S. diplomatic facilities. "Security is our top priority in making this move," wrote Shaun Casey, a State Department adviser on religious matters, in a Nov. 27 blog post.
 
As former U.S. ambassadors to the Holy See, we respectfully suggest that any such security concerns be met by stronger executive leadership in the White House and State Department. The attempt to use such concerns as an excuse for downgrading the Embassy to the Holy See is shameful.
 
The Holy See—the embodiment in international law of the pope's mission as universal pastor of the Catholic Church—was a diplomatic actor centuries before the U.S. was founded, or before modern Italy was born. The Holy See plays a unique and often crucial role in world affairs, from John Paul II's pivotal role in the collapse of European communism, to the important achievements of the Holy See in standing up for human dignity and human rights, and the Vatican's "honest broker" role in international conflicts and in disasters requiring significant and rapid humanitarian aid.
 
The Holy See also plays a distinctive role as a diplomatic hub where more than 175 countries are accredited, and where virtually the entire world is in constant conversation at a level of confidentiality and seriousness that is impossible anywhere elsemost certainly including the United Nations.
 
The U.S. acknowledged all of this by establishing full diplomatic relations with the Holy See. A move to the U.S. Embassy to Italy would downgrade that relationship, as if the U.S.-Holy See relationship were a stepchild of U.S.-Italian relations. That is simply not true, for the range of issues on which America is engaged with the Holy See is broader, and in some respects more consequential, than the dialogue with our good ally, Italy.
 
To downgrade the U.S. Embassy to the Holy See is to ignore the ability of popes to put issues on the agenda of international conversation as no other leaders can. Moving Embassy-Vatican inside Embassy-Italy will not change that fact. But it will signal a lack of U.S. governmental respect for such papal influence, and it will not go unnoticed by other countries.
 
The responsibility of the American diplomatic corps is to advance the country's interests by building international support for actions we believe can create a more stable world for Americans and others. The bedrock of U.S. foreign policy is to promote peace and freedom and to enhance human dignity. As former Secretary of State Henry Kissinger once noted, "America's ultimate challenge is to transform its power into moral consensus, promoting its values, not by imposition but by willing acceptance."
 
Where will America find a more important diplomatic partner today than the Holy See in trying to further its goals of peace and freedom, including religious freedom? It is ironic that just as Pope Francis's influence was reflected by his selection as Time magazine's "Person of the Year," the U.S. seems intent on diminishing its relationship with a person to whom the world is now listening so closely.
 
The Obama State Department likes to apply the term "reset" to its diplomatic efforts. In this case, a reset is indeed in order: one that confirms the independence of the U.S. Embassy to the Holy See and reaffirms the importance that America places on this unique relationship.
 
 
Mr. Flynn was U.S. ambassador to the Holy See under President Bill Clinton. Mr. Nicholson was U.S. ambassador to the Holy See under President George W. Bush.