Why aren't they all called “concordats”?

Why aren't they all called "concordats"?

• First, because some of them aren't. There are different kinds of international agreements and only one type, the treaty, may be called a concordat. A treaty is enforceable under international law, unlike a non-treaty agreement, such as a diplomatic note or a modus vivendi. A concordat implies diplomatic recognition by the Vatican, and to prevent this, agreements concluded with various Communist countries, avoided the international dimension altogether and took the form of a modus vivendi between the Communist government and the local episcopate, tactfully leaving the Vatican out of it. See, for instance, the 1950 modus vivendi with Poland.
   
• There's also terminological confusion in the English-language press when reporters make an honest attempt to explain an unfamiliar word. Since Vatican concordats are almost unknown in the English-speaking world, these are often referred to in the press as accords, bilateral agreements, pacts, settlements, conventions or treaties.
   

• Another reason is that, by the Vatican's won admission, the word concordat isn't used when it could encourage opposition in a countries like France or Brazil with a secular tradition or in post-faschist ones like Italy and Spain that wished to make a break with the past. In general, the word concordat was dropped for a time when, after Vatican II (1962-65), these agreements no longer made the Catholicism the state religion. Franco was the last European dictator who would give the Church exclusive religious rights in a concordat. When Spain became a democracy the "revision" in which they relinquished their role as official state church was pointedly called an accord.
  
   This has a long history: Napoleon avoided using this term for his Concordat of 1801, fearing that the would be regarded as a sellout of the principles of the French Revolution. Instead, he called it a "Convention" and this tactful term was used by a restored Bourbon monarch for two further concordats in 1828.
  
  And in 1929 the papal nuncio Pacelli (the future Pius XII) negotiated a Concordat with social-democratic Prussia. When Lutherans objected, Pacelli suggested calling the Concordat a 'solemn convention.' Everybody was pleased.* Today it is officially titled a "treaty" (Vertrag).
  
  Sometimes this euphemism even seems to be an attempt to get them under the radar of public opinion. When the word "concordat" is unacceptable politically, neither the Vatican, nor the local politicians care to alert the citizens. Then these agreements are disguised under names, such as "convention" or "endorsement". Recent concordats with secularist France from 1974 and 1999 are called — for French consumption — "Endorsements" (Avenants), yet one of them still appears in the list of "Concordats of John Paul II".

  In the case of Brazil, as well, avoidance of the word "concordat" was consistent with the secrecy surrounding the signing of what was called an "Agreement" (Acordo). Different and contradictory reasons were given for this terminology: in one version, that it wasn't a real concordat because it didn't stipulate Holy Days and, in another version, that, though it was a genuine concordat, the word wouldn't be understood by most Brazilians who thought it had to do with "bankruptcy".... However, Vatican Radio delicately hinted at what appears to be the real reason when it stated that "the legal term 'Agreement' [...] poses no problem for the secularity of the state and the democratic and pluralistic legal order". And the Papal Nuncio to Brazil who signed it claimed that "The term ‘agreement’ more easily matches lay terminology", thus avoiding worries about "overlappings and encroachments". (For exactly what was said, see the Appendix at the end.)

• However, it seems to be a matter of what the market will bear. In 1993 the term concordat reappeared as the official title of the Polish concordat and in 2004 with the Portuguese concordat, as well.  
   

Appendix

Below are two different and conflicting accounts of why the Brazilian concordat is called an "Acordo" ("Agreement"): in the first case, because it isn't one, and in the second, because. although it is indeed a concordat, that word can also mean something else in Portuguese (as, for that matter it does in Britain, where it can be a "memorandum of understanding"). However, given Brazil's constitutional tradition of church-state separation, not to mention the President's opposition to the Concordat until recently, it seems likely that the avoidance of the "C-word" has more to do with political calculation. The secrecy with which the concordat was signed and the haste with which it was ratified do nothing to dispel this notion.  

Why was the Agreement with Brazil not called a "Concordat"?
(Por que o acordo com o Brasil não foi chamado de "concordata"?)
Vatican Radio, 25 November 2008.
http://www.radiovaticana.org/bra/Articolo.asp?c=247306

To deserve the name "Concordat" [...] an agreement would have to include all major items concerning the legal status of the Church and the regulation of all so-called "res mixtae" [mixed matters] i.e., the issues that come within the competence of the legal framework of the church [Canon Law], while in the state, such as the civil effects of canonical marriage and religious instruction in schools. Several of these items are included in the [Brazilian] agreement, others, such as the regulation of religious holidays, are not present, for reasons of opportunity.

Moreover, a second reason, also important, is that [...] the term "Concordat" is, according to some, not in harmony with the language of secularism, while the legal term "Agreement" refers to an international agreement between sovereign entities, which poses no problem for the secularity of the state and the democratic and pluralistic legal order. In conclusion, the use of the term "Agreement" expressed, without any ambiguity, the security and respect for secularism of the state.

Why has the term agreement been used and not “concordat”? ("The Agreement between the Holy See and Brazil: An interview with Monsignor Lorenzo Baldisseri, Apostolic Nuncio to Brazil, on the historic agreement between the Holy See and the Latin American giant, signed during the recent visit of President Lula to the Pope") 
30 Days in the Church and the World, 13 November 2008
http://www.30giorni.it/us/articolo.asp?id=19633
 

BALDISSERI: In Brazil the word “concordat” currently refers to a negotiation in the context of bankruptcy proceedings. The term “agreement” was therefore preferred, also because it better fits the modern understanding of relations between Church and State, although the contents of our agreement would authorize one calling it a concordat. Moreover, the term ‘agreement’ more easily matches lay terminology, highlighting more the autonomy and mutual independence of Church and State, in healthy cooperation, but without the danger of the overlappings and encroachments of other historical periods.

* "Peace and the Papacy", Time, 16 August 1943.
http://www.time.com/time/magazine/article/0,9171,933208-3,00.html

(Last updated 14 October 2009)