While the immediate danger is from Pak-based suicide bombers and other attackers, they do not pose a significant national threat (even though, as in Mumbai, the cost is huge to the individuals concerned). We should therefore regard the challenge coming from Pakistan-based individual and small-group attackers as a pimple, or series of pimples.
China is a totally different matter. While it is best for China and India to be friends (something for which I wish many more of us worked), I fear that national compulsions facing China may make it look around for who it can attack - preferably successfully - in order to divert attention from internal problems. As far as I can see, it has only two options that fit the criteria, the Spratly Islands and India. That does not mean that it won't attack Russia or Taiwan (the other two options), but that these are more unlikely targets at present - better equipped to resist, and likely to lead to much greater political complications. The last factor mentioned (complications) also makes the Spratly Islands (which are claimed by several nations - eight, if I recollect aright) less attractive than India.
If, as stated in an interview with The Hindustan Times yesterday by Lieutenant General BS Jaswal (General Officer Commanding, Northern Command), "The Indian Army lags far behind China in military infrastructure along the Line of Actual Control", then it is of the highest importance and urgency to spend the necessary money to upgrade the infrastructure. "China has built all-weather metalled roads leading right up to its border posts facing Tawang in Arunachal Pradesh and Demchok and Fukche in Ladakh....Indian troops, on the other hand, often have to march miles to the front. Roads, where they exist, are dotted with potholes, with long stretches of boulders and slush, leading to accidents that slow down movement. Better connectivity allows the Chinese to cover 400 km a day. The Indian army finds it difficult to cover more than 200 km a day in the forward areas". An army is hugely disadvantaged if it is not as mobile as its opponent.
So what about air power? One to five, apparently: India has "three airfields at Daulat Beg Oldi, Fukche and Nyoma, about 220-250 km east of Leh. But only AN 32 transport planes can land there, so they have no operational value in terms of countering an attack. The only airfield near the China border from where India can deploy warplanes is at Tezpur in Assam, where it has stationed its frontline Sukhoi 30 planes. Chinese military aircraft, however, can reach Shimla, Chandigarh and Leh within five minutes and New Delhi within 20 minutes of taking off from their forward base in Gar Gunsa, across the border, from Demchok in Tibet. It has five such airfields in Tibet where it has stationed warplanes".
So China has at present overwhelming superiority in surface mobility as well as in air power. Chinese soldiers are also better trained and equipped, as far as I can make out. The only disadvantage faced by the Chinese in an attack on India would be if they went beyond the areas they claim, where Chinese soldiers may not feel any sense of conviction in battle. The only advantage possessed by India is that its soldiers would fight for the motherland with full conviction, even in relation to the areas claimed by the Chinese. Conviction is important, but it is the responsibility of the government to provide the best possible training, equipment and facilities so that our soldiers have more than mere rhetoric and sentiment on their side.
Chinese and Indian defence forces may be both riddled with corruption, but what gets through to the bottom level is clearly far more in the case of China than in our case.