China economically, as I've said before, is a 3:1 disparity between the richest provinces (Jiangsu, Zhejiang, Fujian) and the poorest (Gansu, Heilongjiang, Jilin).
Shanghai isn't actually the richest single city in the China; Beijing is.
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As for Indian adventurism, the better example is Fascism, wherein economically unsustainable policies (good economic growth driven by debt) resulted in the necessity of military adventurism to simply prop the political economy up.
When you look at both Nazi Germany and Imperial Japan, they were both stuck in a time trap; i.e, if the Nazis had attacked the Soviet Union at a later time, the Soviets would have had powerful T-34 tank fleets ready to engage the Nazis. If the EoJ had hit China later, the RoC military modernization would have been in a stronger position and instead of Chiang's elite divisions getting wiped out at Shanghai the RoC would have had more elite divisions ready to further slow the Japanese advance, or even repel them altogether.
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Applied to the Sino-Indian situation, Indian senior policymakers are well aware that they need more time in order to "deal with" the Chinese; i.e, China is already a newly developed country and its growth rate is going to slow, between the trade war and the marked Chinese preference for social development as opposed to economic development in the next decade. India, on the other hand, if it can get out of this recession, will likely have around 2-3% real growth advantages over China over the next decade.
China, on the other hand, can't move, because it can't occupy Kashmir without Pakistani Army assistance and the Pakistanis need a lot more anti-tank gear and possibly 5th generation planes to hold off the Indians without resorting to nuclear weapons. The move into Kashmir, likewise, needs the preparation of a Kashmiri insurgency and independence movement before a sudden strike is feasible. Ideally, PLA action against the Indians in Ladakh will be in support of a native insurgency seeking an independent or Pakistani Kashmir. The recent Pakistani provincialization of Gilgit-Baltistan is not a positive move in this scenario because the most promising way to de-Indianize Kashmir is with an independent Kashmir.
Likewise, China's border infrastructure in Tibet, while much better than that of India's, is not sufficient for a full scale war with India. India happens to be a nice compact body, with logistics, despite being deprived of infrastructure, having a low transit time from the Indian core (Uttar Pradesh, despite its low per capita GDP, is the most populous single Indian state). China, on the other hand, has to get everything into the mountains beforehand. This will take years to develop, a period of 5-10 years before Tibet, in logistics terms, is comparable to Xinjiang.
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So in general, while the Chinese situation will decline over the 10-20 year period in terms of relative power, in terms of infrastructure it will improve. The Chinese, like Nazi Germany and Imperial Japan, can't actually strike effectively in the short-term due to the infrastructure gap, but in the long-term the relative force balance will make a Second Sino-Indian War too costly to be worthwhile.
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The obvious moves on both sides would be the upgrading of infrastructure for the Chinese, and the expansion of nuclear arsenals for India and the abandonment of no-first use to provide a credible nuclear deterrent over the border.
On the latter side, the problem is that India wants an aggressive posture and NFU is incompatible with an aggressive posture; the Chinese can only use their ballistic missiles because they have an NFU policy and the Indian side knows the nuclear taboo won't be violated unless they decide to violate it first, but once India itself doesn't have NFU, India is now entitled to use nuclear retaliation against any border transgression. At the same time, the moment NFU is dropped, countries like Sri Lanka, Bangladesh, Nepal, etc, are all going to be scampering to get underneath, primarily, either a Chinese or Pakistani nuclear umbrella, or the nuclear umbrella of other powers (US, European, Russian). Then India has more or less contained itself.
On the former side, preparation of Kashmiri insurgency and Pakistani conventional warfare capabilities can allow a potential Second Sino-Indian War / Third, or is it Fourth, Fifth? Kashmiri War to tip into China's favor provided that India doesn't nuke up fast enough. Infrastructure and logistics would also be a priority; even half of China's strategic potential, focused and aimed at India, would be enough to decimate the InAF and make sure that Kashmir switches hands. This logistical preparation, likewise, is strategically useful in the event that India eventually decides to grow up and join BRI.
