As to why Cardinal Siri did not publically support Lefebvre, I think this interview sheds some light on the subject.  The last paragraph is key...

"No doubt, but he realized he could not go forward because this matter was not understood even by the traditionalists. It seemed to them that the whole controversy concerned the Latin Mass and the real problem was linked to the eighth commandment, the truth. Once again, the Cardinal was right and, above all, he had seen far away. He understood that in the logic of the left there is no being, no sense of reality, and that the ideology, the Cartesian cogito, is totally subjective."


To me it seems that Siri knew that the real problem was the lack of truth, or more exactly the loss of peoples ability to discern truth. Perhaps the destruction of the mass is not the central issue but rather  the fruit of the general decline that started 800 years ago. Furthermore, Siri saw that the errors of V2, the new mass, etc. would not become obvious until well after his death.

2006 interview with Peppino Orlando of Genoa, religious writer and long time friend of Cardinal Siri
"My meeting with Cardinal Siri was at the Citadel, the Pro Civitate of Assisi, where I studied theology for three and a half years, from '58 to '61. Two retreats were dictated to the volunteers by the Cardinal. In this little chapel where we met, Siri was revealed for what he really was: a man of faith, a theologian and man of culture, trying to understand what made a genuine spiritual formation. I was very impressed by these encounters to the point that I asked for an interview with him. The first question he answered, I still remember, it was this. "Your Eminence, I said, what is the key thing that those who want to Christian culture must have?" I figured he would pull out, for example, the Bible. But, he said, ontology, logic and ontology. Without those you cannot possibly go to the Bible, which is the subject of Logos. "Remember, Orlando” - I still remember the words with which he concluded his speech – “that where there is no logic, grace cannot take root." Not surprisingly, modern philosophy, Kant, Hegel and Marx, attacked logic and ontology, indeed, first they attacked the ontology and then the logic.
"Today you are convinced of the validity of this teaching?"
Absolutely . I have remained faithful to this speech. For me, philosophy, spirituality and theology must always be together. Indeed, despite the chaos in which at some point I dived, namely participation Catholic dissent, this was the lifeboat that brought me out of the left.
"What had Siri observed of the world of the left?”
"Without doubt, the illogicalness and the lack of sense of being and of reality. That sense of reality, however, the Cardinal possessed as did the president of Confindustria at the time, Angelo Costa, who I am connected by marriage. Economics, yes, but after the economy the ten commandments. In fact, I often wondered why Siri insisted so much on the eighth. Do not bear false witness.
"Did you get an explanation?"
Certainly. The cardinal wanted to emphasize the absolute value of truth. Another of those values which formed a kind of red thread throughout my life. And this was noticed by my old master of Assisi, which, who, despite my position of leftist dissent of those years, had given orders that I be received in the archbishopric. I remember the discontent of many priests and monsignors, being passed up for an interview with Siri. And I also remember the "grumbles" for example, that His Eminence received more enemies than ever faithful servants of the Church. But anyhow. For me there was always free passage.
 "And what were you talking about in those meetings?"
The Church, the contentions. Friendship with Siri gave me those counter-poisons that, in the long run, would allow me to get out of the left itself. Just that - and that Siri had well understood - the Church of that time and, unfortunately, which today lacks the pope. The Pope is not only the bishop of Rome, but he who holds the authority of government and education, and that strengthens the faith of his brothers. The Council and Paul VI, however, refused the tiara, had somehow deprived the pope of the power of jurisdiction. In short, we have moved from the monarchical principle of Peter in this collegiality, which is based on opinion only.
“Siri therefore had perceived the danger of a loss of the infallible authority of the pope?”
No doubt, but he realized he could not go forward because this matter was not understood even by the traditionalists. It seemed to them that the whole controversy concerned the Latin Mass and the real problem was linked to the eighth commandment, the truth. Once again, the Cardinal was right and, above all, he had seen far away. He understood that in the logic of the left there is no being, no sense of reality, and that the ideology, the Cartesian cogito, is totally subjective."

Whatever Cardinal Siri's failings did doesn't change the fact:

A LOT of Catholics think Traditionalism = the Mass.  

This is what the neotrads count on.

I agree. But was Siri even traditional? He went along with all the reforms until his death.

The Mass is the most visible front piece of the revolution. Saying it's not the only issue is one thing. Acting like it doesn't even matter is another.

A few quotes from Italian sources...
From Vatican Insider 'The Catholic Church Reconquers Genoa'

"Under Siri, the most faithful and authoritative interpreter of the pontificate of Pius XII, Genoa became the stronghold of the defense of Christianity and the cardinal point of reference for a church closer to tradition than innovation, leading it to its isolation from the rest of the country, particularly after the Council."

Published in Il Stampa
"They say that once the old curial Cardinal, Sebastiano Baggio, prefect of the powerful Congregation for Bishops in the last phase of the pontificate of Paul VI and the beginning of that of John Paul II, accused Cardinal Siri of growing his seminarians and priests as an island separate from the body of the Italian Church and that this was not taken into account when they were made bishops. ‘Yes, it's true’ - Siri would respond – ‘we are an island, but my own I taught to swim.’"

Here is testimony from a disgruntled Genoese priest who entered the seminary in 1964 and served for 40 years until his recent banishment.  Father Paolo Farinello, who has no love for Cardinal Siri or for tradition writes in his 2007 book,

“Cardinal Siri, in fact, has never hidden his denigration of the Council and the liturgical reform in particular. In any way he obstructs its implementation in the diocese … We (the seminarians) were trembling with the spirit of the council and each time he (Siri) castrated our passionate enthusiasm by ensuring us that it would take fifty years to remedy the Vatican … He inoculated us unsuspecting with the suspicion that Pope Paul VI was not an orthodox Pope.”

Farinello writes in another article more recently,

“Siri told us ‘do not say the new mass in my diocese, I did not vote for these changes.’”

He understood that in the logic of the left there is no being, no sense of reality, and that the ideology, the Cartesian cogito, is totally subjective."

This Cartesian cogito is the subjective reality preached by Rene Descartes,
"Cogito ergo sum,"  or, I think, therefore I am.  

It basically makes man into a god, one who creates his own existence, for by
the fact of his thinking, he evokes his own reality, and this reality is in the mind.

In fact, the entire objective of the whole system rests on this one sentence:

Reality is in the mind.

That is the foundation of Cartesian philosophy, the keystone of Kantian, Comtian,
Hegelian and Whiteheadian philosophy.  It is the beginning of Modernism, which is
the sewer of all heresies.  It is the source and summit, the headwaters of modern
error and Communism.  When you realize the implications it suddenly becomes
evident that this is no silly game of words.  Hundreds of millions of people have  
died in the wake of this intellectual plague over the past two centuries, and
going on three.  


When he says "...in the logic of the left there is no being," what he is really
saying is, there is no being as we have known being.  The left does have a being
in its logic, but this is not a steadfast and consistent being, for it is subjective
and therefore it changes.  Like Obama said, "change we can believe in."  He
wasn't lying ALL the time!  The God of Christianity does not change, but the
liberal God changes all the time, based on the reality in the mind of the liberal.
The liberal, as Pope St. Pius X explained so well (I think it was actually
Cardinal Merry del Val who was the author) in his monumental encyclical,
Pascendi dominici gregis, evokes God from within.  It all begins when the
philosopher says a 3-word sentence:  



God is immanent.



Three little words, and the whole of Christian civilization is poised to collapse
if Christians simply refuse to recognize the importance of accepting these
three little words in context, or, if they ignore the principle and do not bother
to study, I mean STUDY (not just read) this essential material.  


If you need any help, you can find it.  You are not on your own.  There are a
lot of us in the same boat.  Don't be lazy.   Study.  Learn..................

Question for Neil...

Henry David Thoreau said the there are a thousand people hacking at the branches of evil for the one person hacking at the root. Do you think that the problems with the mass, despite their seriousness, are the fruits of a another problem, the cartesian cogito for instance?

If so, then providing the real mass and properly ordained priests as lefebvre did is not really a solution to our problems.  Not that it wasn't of the utmost importance, or there wasn't an urgent need for it, but in one way it's like hacking at the branches of evil as opposed to the root if Siri is correct in his analysis.

If Siri is right, then the SSPX and other traditional groups could be looked at as a source of temporary relief during the crisis but perhaps expecting a solution from them is a mistake.

I'm not Neil, but I thought I'd put in my two cents.

I think Archbishop Lefebvre (and his true successor, Bishop Williamson) understood the root causes of the crisis, that it stretched back centuries, but he had to do what he could to preserve the traditional Sacraments and traditional Church teaching in the present, because without them, we are doomed. It's important to remember that he considered the SSPX to be "Operation: Survival" rather than the solution to all of the Church's problems. And in this, I think he succeeded.

Imagine if he had retired to a diocese somewhere. A lot fewer people would have been exposed to the truth (myself included).