Is stealth jihad an innovation in Islam?

As to my title question, that's what I've thought all along, mainly because I'd never been aware of any evidence to the contrary -- and secondly, because I reasonably assumed that in pre-modern times, three factors militated against Mohammedans waging stealth jihad:

1) They didn't have to keep up an elaborate pretense of being peaceful and being the friends of the West, because they were more blatantly and honestly arrayed against the West as enemies, having attacked the West relentlessly for at least a solid millennium from the 7th century to the 17th century (only flagging thereafter due to their weakness relative to the stupendously progressive West by that time, but still attacking us).

2) They had no demographic presence within the West, because the West hadn't yet developed the politically correct multi-culturalist stupidity to let them in, in large numbers -- and thus they had no need or opportunity to develop a Fifth Column Trojan Horse (or Trojan Camel) which would, of course, involve the taqiyya complex of deceit that forms the backbone and appendages of stealth jihad proper.

3) In pre-modern times, there was much more symmetry between the West and Islam in terms of military capability and socio-military infrastructure.  Thus, as one major reason (if not the major reason) why Mohammedans deploy stealth jihad is because they find themselves temporarily weaker than their enemy, that reason was far less of a factor in former eras. Indeed, there prevailed a kind of tug-of-war of military parity off and on for centuries, where each success by the West (e.g., Lepanto) was followed by a tragic reversal in favor of Islam (e.g., the battle of La Goulette shortly thereafter).

In this spirit, I would deposit comments here and there over the years expressing this, such as the following at Gates of Vienna back in April of 2011:

To what extent, if any, did Muslims need the modern kind of dhimmitude (which is sort of an anticipatory dhimmitude -- kowtowing to Muslims even before they have conquered you, thus enabling their intended conquest) when they successfully conquered more territory than Alexander the Great or the Romans? Were there key non-Muslims in Persia, India, central Asia, SE Europe, the Roman Christian Middle East, Roman Christian North Africa, and Roman Christian Iberia (Spain) who were this kind of modern dhimmi, helping pave the way for the conquest of Muslims?

My instinct (absent enough historical information) is to answer no: It seems that historically, the stupendous expansion of Islam was due mainly to frontal assault using fanatically supercharged and rabid ultra-violence...

More recently, however, I've come across indications from history that may show that Muslims did in fact deploy a stealth jihad in long-term preparation for more concerted jihad of the sword.  The indications are enfolded in the data discussed in an obscure academic journal article, "The Coming of Islam to the East Indies" by G.E. Marrison, published in the Journal of the Malaysian Branch of the Royal Asiatic Society, Vol. 24, No. 1 (154), February 1951, pp. 28-37.

The author, Prof. Marrison, in this article was not concerned to delve into (much less notice) the phenomenon of stealth jihad; but his indirect (and unintentional) evidence the reader can palpate between the lines, and it implies an interesting process:

1) During the long jihad against India, the Islamic conquest of the Subcontinent proceeded in piecemeal fashion, with advances, then reversals, all because the native Indians at various times and localities fought back (and at times won ground, or retook ground).

2) For a time early on (9th century forward), apparently, southern India remained a region the Muslims were unable to conquer, at least in any comprehensive sense.

3) Lacking a solid military home base in southern India, therefore, when Muslims continued their inexorable Drang nach Osten (part & parcel with their Drang nach Westen, and both subsets of their overarching fanatical mania for a global Lebensraum) by expanding eastward into the archipelagos of what the French later called L'Insulinde -- basically SE Asia and all the island cultures that extend southward (Malaysia, Indonesia) and eastward (Philippines) -- they did not do so as frank military conquerors.

4) We reasonably assume at this juncture in our analysis that the expanding Muslims did not conquer at that point, not because they didn't want to (as Western idiots assume), but because at the time they were unable to do so in any feasible way.  Their expansion into areas like Indonesia thus resembles a peaceful osmosis of "Muslim traders" (as our stupid Western historians put it) simply peacefully "expanding" while over time Islam just "took root" like some kind of creeping ivy, growing organically without any bloodshed.  The process resembled this because, in that phase of Islamic expansion, that's what Muslims knew they had to do, to lay down layers of insidious, seemingly pacific expansion in preparation for later military assaults.

5) Thus, apparently, during that first wave or phase of expansion, Muslims pretended to be peaceful and to forge alliances with local chieftains and native rulers in various primitive island communities, in the process over a long period of time (perhaps a century) insinuating themselves into the diverse fabric of all those various archipelago cultural systems.  Then when the time came that they had the military wherewithal -- a more substantial military home base in southern India -- they finished the job with violence.

That's the theory, at any rate.  What it requires is some more solid academic research which, in the lamentable state of current academic studies in relation to Islam where whitewashing propaganda more often than not substitutes for actual historiography and sociology, seems unlikely to occur any time soon.

There also could be variations of the above 5-point theory -- such as the possibility that during that first wave or phase of stealth jihad in Insulindia, there were many instances and episodes of violent strong-arming, including assassinations and terrorist razzias (and threats of same), if only because here and there local rulers or people resented the increasing intrusion of Islam and resisted. But there was not the massive violence of a frank military assault.

And, of course, the same theoretical template could be applied analytically to other global regions and eras of Islamic expansion -- most notably the Spanish peninsula and the Byzantine incursions.