Even with the Thule influencing Europe in strange and interesting ways, I can't think of any way that the Thule could derail the European trajectory enough to stop something like the 19th Century industrial subjugation of pretty much the entire planet happening within +/-100 years of when it did in our history. If anything, it is most likely that the Thule accelerate the rise of Europe since Europe is best placed to trade with them and is best placed to take advantage of the new Thule crops. Nor do I think the Thule interaction with Europe is likely to make the white man significantly more enlightened at the time when Europe is riding high on the industrial revolution.
So my bet is that "colonization" as we term it does happen, and even if the Thule manage to escape the worst of it, they still experience some degree of European subjugation.
fasquardon
This is pretty much what I've said upthread, but with some qualifications:
1) As Hobelhouse says in the next post, what European wants to live in the friggin' Arctic? OTL of course lots wound up living in the tropics, the Arctic might be no worse and perhaps better from their POV--but no tropical European colony, however desired and even vital to their imperial schemes, ever got demographically or even culturally overwhelmed. One might point to the tropics of Australia, but that's something of a special case, Australia having been a very low population density and very technologically primitive place, and the fact that modern Australia claims tropical lands is a bit misleading--the population base overwhelmingly lives in the much more temperate southern coastal areas, and just keeps an outpost sort of foothold on the low tropical northern coast. Much as modern Canada has its high Arctic on the map, and patrols it, but hardly any Canadians who aren't of Inuit or other high Arctic Native descent live there.
If there had been a civilization comparable to the levels prevailing in Indonesia in the 16th century along the north Australian coast, the modern nation might not have that region included in its territory at all, and if it did, it would be a distinct subregion with very strong Native presence and culture and probably involve quite a lot of political friction.
The Europeans who do move into the Arctic will most likely be Northern Europeans, and as the timeline has already developed (if all good powers permitting, DValdron comes back and continues it, pretty please?
) we see Scandinavia (greater Scandinavia, including Iceland) getting drawn in already. But in a fashion where the Thule cultural influence is already reacting strongly on their own societies; if this be European colonialism, it is of a different mode, one tending to create a hybrid, synergistic new society, which might serve as an early channel of transforming native Thule societies on their own terms to be more on an even technical level with European ones. Contact is not waiting on the convenience of great European empires moving into unclaimed, forbidding, largely empty territories in good time when they are much more developed, it is happening in the earliest days of European expansion, and yet unlike Mexico or Peru, highly unlikely to attract a flood of European colonists to transform the place by sheer numbers.
2) this leads to my "Ice Arab/Arctic Fastness" concepts which I've gone on about before and have little time to reiterate here. The Arctic is vast and forbidding enough, and the Thule competent enough at living there, that even a sustained and determined effort to subjugate the Thule lands will take time and be hard fought, while meanwhile the Thule have time to rally and for separate Thule states to negotiate positions within the evolving European system. I believe that there will be regions in the Arctic and high subArctic (in Asia especially) where Thule or Thule-dominated or cross-pollinated states will emerge that survive as at least nominally independent right up to modern times.
3)Meanwhile, regions of the rest of the world will eventually be transformed by the eventual spread of Thule agricultural package to enhance the productivity and hence population of a number of places, notably highlands. If Scotland or Switzerland are transformed, that doesn't change the big picture of European capitalist civilization still covering the world, true. What if it's Tibet though?
I have to admit, the vectors than can bring a suitable form of Thule package to Tibet don't seem likely to emerge until pretty late, mid-19th century is my guess. By then--but only by then--European agricultural science will have finally addressed the problem of the nature of the Arctic package and assimilated knowledge of how to grow these crops and where they might do well. By then, perhaps a century before then, some Thule crops will have developed markets in Europe and elsewhere and plantations that can provide more will be desired. By then, the vexed question of China's claim on Tibet will probably be eased by the general collapse of the Chinese state and disarray of its society under the assault of capitalistic trade. It is not so clear there would be a European power comparable to the British Raj of OTL running things in India, or anyway the Ganges valley, but it seems at any rate probable there would be some sort of channel for Europeans to come up against the Himalayas somehow.
So Tibet would have Thule crops introduced in the form of European-owned plantations--probably not as a straight European colony or protectorate as on paper Tibet remains a Chinese possession and it probably would not be in the general European interest to carve the place off just yet. By the mid-20th century, the crops will have spread from plantations to the general population which will be significantly larger--in the turmoil one can anticipate for China, I daresay a Tibetan state
will split off then. And have the demographics, combined with forbidding geography and the support of First World patron powers, to deter a later Chinese reconquest.
This whole last point 3) is hardly an argument for a world deeply transformed, as Tibet and the strengthened (anyway more populous) Andean states we can also anticipate will hardly change the balance of power in the world. But it would be a somewhat different world anyway.
Heck, someone might even try settling the Antarctic coast and thus claim all of Antarctica as the colony of some European or other Western power!