China don't have any Arctic territory, so none of this applies to their army.Presumably this applies to the Russians and Chinese too?
The conditions in Arctic Russia are very similar to those in US territory.
Has armoured warfare even taken place in an Arctic environment? Is it really a place for vehicles that are sixty or more tonnes?
Since this is in response to a US army paper on operating in Alaska, I'll just quote from the document itself.
Lacking the climate- moderating effect of the warm Gulf Stream, the North American Arctic hosts a much harsher environment than the European Arctic and significantly less road and maritime infrastructure. Base infrastructure materials across the region need to have high thermal efficiency; long-term durability; tolerance to repeated freeze and thaw cycles; and resistance to permafrost degradation. Infrastructure in many austere locations has already deteriorated due to extreme environmental factors. It can also complicate force sustainment operations as roadways, sea ports, and airfields are potentially rendered inoperable. The loss of sea ice index opens up new waterways that can allow increased access to and transit through the region. This could require additional forces, equipment capability, and infrastructure investments to secure the U.S. homeland and the northern avenues of approach.
The Arctic, however, is not challenging solely due to extreme cold temperatures. In many instances, mobility is actually at its highest state in the winter. Summer poses significant challenges for many wheeled vehicles, while the most challenging period is the spring thaw when ground movement becomes impossible across considerable swaths of territory. Regardless of season, mobility by air is critical to Army operations. Today and for the foreseeable future, the Arctic presents a harsh and demanding environment for Army operations and activities.
A multi-domain capable Army creates new options for joint force commanders to achieve their missions. The Arctic, however, poses some particular challenges. The significant distances, lack of commercial and military infrastructure, and harsh climate have historically made Arctic campaigns contests of relatively small and dispersed forces operating at the limits of operational feasibility. This small margin of error has generally had two implications. First, the quality of individuals and units has often been decisive. The side best able to overcome challenges has tended to prevail. For this reason, the mindset or ethos of Arctic units has been an even more important element than any specialized equipment. Second, the environment favours the defence more heavily than in other climates. It has been difficult for attacking forces to achieve numerical superiority without pushing sustainment to its limits. The loss of one key logistics node, the failure of one convoy, the destruction of one critical bridge, or the stubborn resistance of one strong point along a line of communications has brought many Arctic operations to an unsuccessful close.
The US have historically not taken operations in the Arctic very seriously. Their main military interest in Alaska has been as a location for radar stations and as a transit point across the Pacific (remember that the earth is a globe, it's not flat). They generally count on the remoteness of it for defence.
The Americans currently appear to be going through one of their periodic spates of interest in the Arctic. Whether that will be sustained is a good question. Here's a previous opinion.
A seasoned former Finnish army officer hinted at the challenge this situation posed for the United States when, after assisting with a small exercise in Alaska in 1948, he observed, “American infantry winter warfare ability is such that unless a miracle happens, the Russian Ski Divisions will cut these infantry divisions to pieces without mercy.”