Vatican II spoke of the Muslims only briefly, and only in minor sections of two documents:

I. Lumen Gentium [Dogmatic Constitution on the Church], November 21, 1964. This document, which is 77 pages long in the edition I have, devotes one sentence to Muslims. Here is the quotation from Chapter II in context (the entire document can be found at http://abbey.apana.org.au/Councils/vatican2/V2church.Htm):

                     CHAPTER II THE PEOPLE OF GOD

   9. At all times and in every race, anyone who fears God and does what
   is right has been acceptable to him (cf. Acts 10:35). He has, however,
   willed to make men holy and save them, not as individuals without any
   bond or link between them, but rather to make them into a people who
   might acknowledge him and serve him in holiness. He therefore chose
   the Israelite race to be his own people and established a covenant
   with it. He gradually instructed this people -- in its history
   manifesting both himself and the decree of his will -and made it holy
   unto himself. All these things, however, happened as a preparation and
   figure of that new and perfect covenant which was to be ratified in
   Christ, and of the fuller revelation which was to be given through the
   Word of God made flesh. "Behold the days are coming, says the Lord,
   when I will make a new covenant with the house of Israel and the house
   of Judah. . . I will put my law within them, and I will write it upon
   their hearts, and they shall be my people . . . For they shall all
   know me from the least of them to the greatest, says the Lord" (Jer.
   31:31-34). Christ instituted this new covenant, namely the new
   covenant in his blood (cf. 1 Cor. 11: 25 ); he called a race made up
   of Jews and Gentiles which would be one, not according to the flesh,
   but in the Spirit, and this race would be the new People of God. For
   those who believe in Christ, who are reborn, not from a corruptible
   seed, but from an incorruptible one through the word of the living God
   (cf. 1 Pet. 1:23), not from flesh, but from water and the Holy Spirit
   (cf. Jn. 3:56), are finally established as "a chosen race, a royal
   priesthood, a holy nation . . . who in times past were not a people,
   but now are the People of God" (1 Pet. 2:910).

   [....]

   [The document goes on to discuss all those outside the Catholic
   Church, their degree of closeness to the Church, and the amount
   of truth they possess.]

   All men are called to this catholic unity which prefigures and promotes
   universal peace. And in different ways to it belong, or are related:
   the Catholic faithful, others who believe in Christ, and finally all
   mankind, called by God's grace to salvation.

   14. This holy Council first of all turns its attention to the Catholic
   faithful. Basing itself on scripture and tradition, it teaches that
   the Church, a pilgrim now on earth, is necessary for salvation: the
   one Christ is mediator and the way of salvation; he is present to us
   in his body which is the Church. He himself explicitly asserted the
   necessity of faith and baptism (cf. Mk. 16:16; Jn. 3:5), and thereby
   affirmed at the same time the necessity of the Church which men enter
   through baptism as through a door. Hence they could not be saved who,
   knowing that the Catholic Church was founded as necessary by God
   through Christ, would refuse either to enter it, or to remain in it.

   Fully incorporated into the Church are those who, possessing the
   Spirit of Christ, accept all the means of salvation given to the
   Church together with her entire organization, and who -- by the bonds
   constituted by the profession of faith, the sacraments, ecclesiastical
   government, and communion -- are joined in the visible structure of
   the Church of Christ, who rules her through the Supreme Pontiff and
   the bishops. Even though incorporated into the Church, one who does
   not however persevere in charity is not saved. He remains indeed in
   the bosom of the Church, but "in body" not "in heart.''[12] All
   children of the Church should nevertheless remember that their exalted
   condition results, not from their own merits, but from the grace of
   Christ. If they fail to respond in thought, word and deed to that
   grace, not only shall they not be saved, but they shall be the more
   severely judged.[13]

   Catechumens who, moved by the Holy Spirit, desire with an explicit
   intention to be incorporated into the Church, are by that very
   intention joined to her. With love and solicitude mother Church
   already embraces them as her own.

   15. The Church knows that she is joined in many ways to the baptized
   who are honored by the name of Christian, but who do not however
   profess the Catholic faith in its entirety or have not preserved unity
   or communion under the successor of Peter.[14] For there are many who
   hold sacred scripture in honor as a rule of faith and of life, who
   have a sincere religious zeal, who lovingly believe in God the Father
   Almighty and in Christ, the Son of God and the Saviour,[15] who are
   sealed by baptism which unites them to Christ, and who indeed
   recognize and receive other sacraments in their own Churches or
   ecclesiastical communities. Many of them possess the episcopate,
   celebrate the holy Eucharist and cultivate devotion of the Virgin
   Mother of God.[16] There is furthermore a sharing in prayer and
   spiritual benefits; these Christians are indeed in some real way
   joined to us in the Holy Spirit for, by his gifts and graces, his
   sanctifying power is also active in them and he has strengthened some
   of them even to the shedding of their blood. And so the Spirit stirs
   up desires and actions in all of Christ's disciples in order that all
   may be peaceably united, as Christ ordained, in one flock under one
   shepherd.[17] Mother Church never ceases to pray, hope and work that
   this may be achieved, and she exhorts her children to purification and
   renewal so that the sign of Christ may shine more brightly over the
   face of the Church.

   16. Finally, those who have not yet received the Gospel are related to
   the People of God in various ways.[18] There is, first, that people to
   which the covenants and promises were made, and from which Christ was
   born according to the flesh (cf. Rom. 9 :4-5): in view of the divine
   choice, they are a people most dear for the sake of the fathers, for
*  the gifts of God are without repentance (cf. Rom. 11:29-29). But the
*  plan of salvation also includes those who acknowledge the Creator, in
*  the first place amongst whom are the Moslems: these profess to hold
*  the faith of Abraham, and together with us they adore the one,
*  merciful God, mankind's judge on the last day. Nor is God remote from
   those who in shadows and images seek the unknown God, since he gives
   to all men life and breath and all things (cf. Acts 17:2528), and
   since the Savior wills all men to be saved (cf. 1 Tim. 2:4). Those
   who, through no fault of their own, do not know the Gospel of Christ
   or his Church, but who nevertheless seek God with a sincere heart,
   and, moved by grace, try in their actions to do his will as they know
   it through the dictates of their conscience -- those too many achieve
   eternal salvation.[19] Nor shall divine providence deny the assistance
   necessary for salvation to those who, without any fault of theirs,
   have not yet arrived at an explicit knowledge of God, and who, not
   without grace, strive to lead a good life. Whatever good or truth is
   found amongst them is considered by the Church to be a preparation for
   the Gospel[20] and given by him who enlightens all men that they may
   at length have life. But very often, deceived by the Evil One, men
   have become vain in their reasonings, have exchanged the truth of God
   for a lie and served the world rather than the Creator (cf. Rom. 1:21
   and 25). Or else, living and dying in this world without God, they are
   exposed to ultimate despair. Hence to procure the glory of God and the
   salvation of all these, the Church, mindful of the Lord's command,
   "preach the Gospel to every creature" (Mk. 16:16) takes zealous care
   to foster the missions.

   17. As he had been sent by the Father, the Son himself sent the
   apostles (cf. Jn. 20:21) saying, "go, therefore, and make disciples of
   all nations, baptizing them in the name of the Father, and of the Son,
   and of the Holy Spirit, teaching them to observe all that I have
   commanded you; and behold I am with you all days even unto the
   consummation of the world" (Mt. 28:18-20). ...

The Muslims are there, sandwiched between the Jews and other religions. But all this document recognizes, even with its flowery language, is the following:

1. Muslims acknowledge the Creator.

2. Muslims profess to hold the faith of Abraham (i.e., they claim that they have the same faith Abraham had).

3. Like Catholics, Muslims adore (i.e., worship) God, and regard Him as one, merciful, and judging.

No mention of Muhammad, the Qur'an, or what "Islam" teaches, only what "Muslims" at present believe. And, from my knowledge of the language of Church documents like this, I would not argue that "Muslims" is meant to include every single person who calls himself a Muslim, but only the mass of Muslims in general.

II. Nostra Aetate [Declaration on the Relation of the Church to Non-Christian Religions], October 28, 1965. This document, 4 pages long, devotes slightly less than half a page to Muslims. Here is the quotation in context (the entire translated document can be found at http://abbey.apana.org.au/Councils/vatican2/V2non.Htm):

    DECLARATION ON THE RELATION OF THE CHURCH TO NON-CHRISTIAN RELIGIONS

                               Nostra Aetate

                              October 28 1965

   1. In this age of ours, when men are drawing more closely together and
   the bonds of friendship between different peoples are being
   strengthened the Church examines with greater care the relation which
   she has to non-Christian religions. Ever aware of her duty to foster
   unity and charity among individuals, and even among nations, she
   reflects at the outset on what men have in common and what tends to
   promote fellowship among them.

   All men form but one community. This is so because all stem from the
   one stock which God created to people the entire earth (cf. Acts
   17:26), and also because all share a common destiny, namely God. His
   providence, evident goodness, and saving designs extend to all men
   (cf. Wis. 8:1: Acts 14:17: Rom. 2:6 7: I Tim. 2:4) against the day
   when the elect are gathered together in the holy city which is
   illumined by the glory of God, and in whose splendor all peoples will
   walk(cf. Apoc 21:23 ff.).

   Men look to their different religions for an answer to the unsolved
   riddles of human existence. The problems that weigh heavily on the
   hearts of men are the same today as in the ages past. What is man?
   What is the meaning and purpose of life? What is upright behavior, and
   what is sinful? Where does suffering originate, and what end does it
   serve? How can genuine happiness be found? What happens at death? What
   is judgment? What reward follows death? And finally, what is the
   ultimate mystery, beyond human explanation, which embraces our entire
   existence, from which we take our origin and towards which we tend?

   2. Throughout history even to the present day, there is found among
   different peoples a certain awareness of a hidden power, which lies
   behind the course of nature and the events of human life. At times
   there is present even a recognition of a supreme being or still more
   of a Father. This awareness and recognition results in a way of life
   that is imbued with a deep religious sense. The religions which are
   found in more advanced civilizations endeavor by way of well-defined
   concepts and exact language to answer these questions. Thus in
   Hinduism men explore the divine mystery and express it both in the
   limitless riches of myth and the accurately defined insights of
   philosophy. They seek release from the trials of the present life by
   ascetical practices, profound meditation and recourse to God in
   confidence and love. Buddhism in its various forms testifies to the
   essential inadequacy of this changing world. It proposes a way of life
   by which men can with confidence and trust, attain a state of perfect
   liberation and reach supreme illumination either through their own
   efforts or by the aid of divine help. So. too, other religions which
   are found throughout the world attempt in their own ways to calm the
   hearts of men by outlining a program of life covering doctrine, moral
   precepts and sacred rites.

   The Catholic Church rejects nothing of what is true and holy in these
   religions. She has a high regard for the manner of life and conduct,
   the precepts and doctrines which, although differing in many ways from
   her own teaching, nevertheless often reflect a ray of that truth which
   enlightens all men. Yet she proclaims and is in duty bound to proclaim
   without fail, Christ who is the way, the truth and the life (Jn. 1:6).
   In him, in whom God reconciled all things to himself (2 Cor. 5:18-19),
   men find the fullness of their religious life.

   The Church therefore, urges her sons to enter with prudence and
   charity into discussion and collaboration with members of other
   religions. Let Christians, while witnessing to their own faith and way
   of life, acknowledge, preserve and encourage the spiritual and moral
   truths found among non-Christians, also their social life and culture.

*  3. The Church has also a high regard for the Muslims. They worship
*  God, who is one, living and subsistent, merciful and almighty, the
*  Creator of heaven and earth,[1] who has also spoken to men. They
*  strive to submit themselves without reserve to the bidden decrees of
*  God, just as Abraham submitted himself to God's plan, to whose faith
*  Muslims eagerly link their own. Although not acknowledging him as God,
*  they worship Jesus as a prophet, his virgin Mother they also honor,
*  and even at times devoutly invoke. Further, they await the day of
*  judgment and the reward of God following the resurrection of the dead.
*  For this reason they highly esteem an upright life and worship God,
*  especially by way of prayer, alms-deeds and fasting.
*
*  Over the centuries many quarrels and dissensions have arisen between
*  Christians and Muslims. The sacred Council now pleads with all to
*  forget the past, and urges that a sincere effort be made to achieve
*  mutual understanding; for the benefit of all men, let them together
*  preserve and promote peace, liberty, social justice and moral values.

   4. Sounding the depths of the mystery which is the Church, this sacred
   Council remembers the spiritual ties which link the people of the New
   Covenant to the stock of Abraham.

   The Church of Christ acknowledges that in God's plan of salvation the
   beginning of her faith and election is to be found in the patriarchs.
   Moses and the prophets. She professes that all Christ's faithful, who
   as men of faith are sons of Abraham (cf. Gal. 3:7), are included in
   the same patriarch's call and that the salvation of the Church is
   mystically prefigured in the exodus of God's chosen people from the
   ....

   [1. Cf. St. Gregory VII, Letter 21 to Anzir (Nacir), King of
   Mauretania (PL, 148, col. 450 ff.).]

So here the Muslims appear, after the Buddhists and before the Jews. Because this document is concerned specifically with non-Christian religions, it talks more about Muslims than Lumen Gentium does. Nevertheless, all it claims about Muslims is the following:

1. The Catholic Church has a high regard for Muslims. (This "regard" is genuine, but it should not be exaggerated, since Church documents are always written in a polite diplomatic language wherein even a power-hungry king who has just plundered papal lands can be referred to as an "august and pacific ruler".)

2. Muslims worship God. (More so than in Lumen Gentium, the Church seems to declare as a fact here that Muslims regard God as one, living, subsistent, merciful, almighty, and as having "spoken to men". Note that the last phrase means only that "They worship God, ... who has spoken to men." There is no recognition of Muhammad or the Qur'an necessarily implied here.)

3. Muslims try to submit to God's will, which is hidden, just as Abraham submitted.

4. Muslims eagerly link their faith to that of Abraham. (I.e., they claim their faith is the same as Abraham's.)

5. Muslim do not acknowledge Jesus as God, but do worship him as a prophet. (Here "worship" would seem to be a flowery term denoting a reverence or adoration less than what one would give to a deity.)

6. Muslims also honor and sometimes devoutly invoke Mary. (The sentence also implies that Muslims accept Mary's virginity.)

7. Muslims believe in a day of judgment and the reward of God following the resurrection of the dead.

8. Muslims highly esteem an upright life.

9. Muslims worship God, especially by way of prayer, alms-deeds and fasting.

10. Muslims and Christians have quarreled many times.

Again, no recognition of Muhammad, the Qur'an, the correctness of what Muhammad taught, or any assertion that what "Muslims" believe today is necessarily identical with what Muhammad taught. It is recognized that there is some truth among Muslims, but there is no recognition given of any specific revelation except to the Jews and Christians. So, as becomes clear in other Church documents, whatever truth there may be in what Muslims believe must come either from the universal truths that God has always made accessible to the minds and hearts of all people, or else by transmission from the divine revelation granted to the Jews and Christians.

I hope this will help you to dispel the misunderstandings about Vatican II that appear so frequently.

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