The Superiors General of the Fraternity of St Peter, the Institute of Christ the King Sovereign Priest, the Institute of the Good Shepherd, and a number of other Superiors General of priestly institutes and religious communities attached to the Traditional Mass (including three communities of women), have issued a joint letter in response to
Traditionis Custodes. Here it is, on the FSSP website. It is addressed to the Bishops of France, not, as some have assumed, to the Holy See.
As befits such a document, it is carefully worded. In principle, Traditionis Custodes creates an impossible situation for the signatories. They are founded on the charism of the Traditional liturgy, and the Letter accompanying Traditionis Custodes tells us that it is the intention of the document that in the longer term this liturgy should entirely disappear. Furthermore, the justification for this given in the Letter is that the clergy and faithful (who are not distinguished) are detached in some sense from the unity of the Church.
The argument which needs to be made to the Bishops of France at this point is thus a delicate one. Negatively, it should be obvious that to strike a defiant attitude, to threaten disobedience to Traditionis Custodes or the Bishops, or to suggest that they might go over to the Society of Pius X, would serve to confirm the purported justification of Traditionis Custodes. It would be directly counter-productive.